Immunostimulatory oligoribonucleotides

ABSTRACT

The invention provides immunostimulatory compositions and use of those compounds in the preparation of medicaments for the treatment of disease as well as in vitro uses. In particular, the compositions of the invention include immunostimulatory oligoribonucleotides that incorporate a sequence-dependent immunostimulatory sequence motif. Specific modifications involving phosphate linkages, nucleotide analogs, adducts, and combinations thereof are provided. Compositions of the invention, which optionally can include an antigen, can be used alone or together with other treatments to stimulate or enhance an immune response. Also provided are compositions and methods useful for treating a subject having an infection, a cancer, an allergic condition, asthma, airway remodeling, or immunodeficiency. Immunostimulatory oligoribonucleotides of the invention are believed to stimulate Toll-like receptor 8 (TLR8).

RELATED APPLICATION

This application claims priority under 35 USC §119 to U.S. ProvisionalApplication No. 60/739,529, filed Nov. 25, 2005 and U.S. ProvisionalApplication No. 60/778,989, filed Mar. 3, 2006, the entire contents ofwhich are hereby incorporated by reference.

FIELD OF THE INVENTION

The invention relates generally to the field of immunology, and moreparticularly to immunostimulatory molecules. More specifically theinvention relates to ribonucleic acid (RNA) molecules, includingoligoribonucleotides, with immunostimulatory activity.

BACKGROUND OF THE INVENTION

Toll-like receptors (TLRs) are a family of highly conserved patternrecognition receptor (PRR) polypeptides that recognizepathogen-associated molecular patterns (PAMPs) and play a critical rolein innate immunity in mammals. Currently at least ten family members,designated TLR1-TLR10, have been identified. The cytoplasmic domains ofthe various TLRs are characterized by a Toll-interleukin 1 receptor(TIR) domain. Medzhitov R et al. (1998) Mol Cell 2:253-8. Recognition ofmicrobial invasion by TLRs triggers activation of a signaling cascadethat is evolutionarily conserved in Drosophila and mammals. The TIRdomain-containing adapter protein MyD88 has been reported to associatewith TLRs and to recruit interleukin 1 receptor-associated kinase (IRAK)and tumor necrosis factor (TNF) receptor-associated factor 6 (TRAF6) tothe TLRs. The MyD88-dependent signaling pathway is believed to lead toactivation of NF-κB transcription factors and c-Jun NH₂ terminal kinase(Jnk) mitogen-activated protein kinases (MAPKs), critical steps inimmune activation and production of inflammatory cytokines. For reviews,see Aderem A et al. (2000) Nature 406:782-87, and Akira S et al. (2004)Nat Rev Immunol 4:499-511.

A number of specific TLR ligands have been identified. Ligands for TLR2include peptidoglycan and lipopeptides. Yoshimura A et al. (1999) JImmunol 163:1-5; Yoshimura A et al. (1999) J Immunol 163:1-5; AliprantisA O et al. (1999) Science 285:736-9. Lipopolysaccharide (LPS) is aligand for TLR4. Poltorak A et al. (1998) Science 282:2085-8; Hoshino Ket al. (1999) J Immunol 162:3749-52. Bacterial flagellin is a ligand forTLR5. Hayashi F et al. (2001) Nature 410:1099-1103. Peptidoglycan hasbeen reported to be a ligand not only for TLR2 but also for TLR6.Ozinsky A et al. (2000) Proc Natl Acad Sci USA 97:13766-71; Takeuchi Oet al. (2001) Int Immunol 13:933-40. Recently certain low molecularweight synthetic compounds, the imidazoquinolines imiquimod (R-837) andresiquimod (R-848), were reported to be ligands of TLR7 and TLR8. HemmiH et al. (2002) Nat Immunol 3:196-200; Jurk M et al. (2002) Nat Immunol3:499.

Beginning with the recent discovery that unmethylated bacterial DNA andsynthetic analogs thereof (CpG DNA) are ligands for TLR9 (Hemmi H et al.(2000) Nature 408:740-5; Bauer S et al. (2001) Proc Natl Acad Sci USA98, 9237-42), it has been reported that ligands for certain TLRs includecertain nucleic acid molecules. Recently it has been reported thatcertain types of RNA are immunostimulatory in a sequence-independent orsequence-dependent manner. Further, it has been reported that thesevarious immunostimulatory RNAs stimulate TLR3, TLR7, or TLR8.

SUMMARY OF THE INVENTION

The invention relates generally to immunostimulatoryoligoribonucleotides (ORN) that contain certain immunostimulatory RNAmotifs, as well as to related immunostimulatory compositions containingsuch immunostimulatory ORN, and methods for the use of suchimmunostimulatory ORN and compositions. The immunostimulatory ORN of theinvention are useful in any setting or application that calls forstimulating or augmenting an immune response. As disclosed below, theimmunostimulatory ORN of the invention are of particular use in thepreparation of pharmaceutical compositions, including adjuvants,vaccines, and other medicaments, for use in treating a variety ofconditions, including infection, cancer, allergy, and asthma. Theinvention in certain aspects thus relates to immunostimulatorycompositions that include immunostimulatory ORN of the invention, aswell as methods of their use. Also as disclosed below, theimmunostimulatory ORN and immunostimulatory compositions of theinvention are of particular use in methods for activating an immunecell, vaccinating a subject, treating a subject having an immune systemdeficiency, treating a subject having an infection, treating a subjecthaving autoimmune disease, treating a subject having cancer, treating asubject having an allergic condition, treating a subject having asthma,airway remodeling, promoting epitope spreading, and antibody-dependentcellular cytotoxicity (ADCC).

As disclosed in greater detail below, the immunostimulatory ORN of theinvention are characterized by their inclusion of at least onesequence-dependent immunostimulatory RNA motif. The sequence-dependentimmunostimulatory RNA motif generally is a short RNA sequence, althoughin certain embodiments the motif can also include a modification such asa modified internucleotide phosphate linkage, a modified nucleobase, amodified sugar, a nucleotide analog, or any combination thereof. Asdescribed in detail below, in one embodiment the immunostimulatory RNAmotif occurs in the context of a longer immunostimulatory ORN of theinvention. Also the immunostimulatory RNA motif may occur in the contextof a chimeric DNA:RNA nucleic acid molecule.

The sequence-dependent immunostimulatory RNA motifs andimmunostimulatory ORN incorporating such motifs are disclosed to beagonists for TLR8. More particularly, at least certain of thesequence-dependent immunostimulatory RNA motifs, immunostimulatory ORN,and immunostimulatory chimeric DNA:RNA nucleic acid molecules aredisclosed to be agonists of TLR8 but not agonists of TLR7.

The immunostimulatory RNA motif according to some aspects of theinvention is N-U-R₁-R₂.

N is a ribonucleotide and N does not include a U. In some embodiments Nis Adenosine or Cytosine (C) or derivatives thereof.

U is Uracil or a derivative thereof.

R is a ribonucleotide wherein at least one of R₁ and R₂ is Adenosine (A)or Cytosine or derivatives thereof. R is not U unless N-U-R₁-R₂ includesat least two A.

The ORN of the invention includes at least one and in some embodimentsmore than one (i.e., 2, 3, or 4) immunostimulatory motifs, N-U-R₁-R₂.The ORN does not include a TLR7/8 motif. The ORN is preferably 4-100 inlength and optionally includes at least one backbone modification.

N-U-R₁-R₂ may in some embodiments include at least 3 As or at least 2Cs. Optionally, N-U-R₁-R₂ includes at least one G or C.

In some embodiments the ORN is not ACCCAUCUAUUAUAUAACUC (SEQ ID NO:89).

In other embodiments the ORN motif is separated from a 5′ ribonucleotideby a non-nucleotide linker. In yet other embodiments the ORN motif isseparated from a 3′ ribonucleotide by a non-nucleotide linker.Optionally, the ORN motif is separated from a 5′ and 3′ ribonucleotideby a non-nucleotide linker.

The ORN may further comprise a pharmaceutically acceptable carrier whichoptionally is a lipid carrier such asN-[1-(2,3-Dioleoyloxy)propyl]-N,N,Ntrimethylammoniummethyl-sulfate(DOTAP). In other embodiments the ORN is not complexed to DOTAP.

The ORN may be single stranded or double stranded.

In other embodiments the ORN includes at least one AU. In yet otherembodiments the ORN includes at least one CU.

In some embodiments the ORN is one of the following: A*U*A*G*G*C*A*C,(SEQ ID NO:4) G*C*C*A*C*C*G*A*G*C*C*G*A*A*U*A*U*A* (SEQ ID NO:11) C*C,A*U*A*U*A*U*A*U*A*U*A*U*A*U*A*U*A*U* (SEQ ID NO:12) A*U,U*U*A*U*U*A*U*U*A*U*U*A*U*U*A*U*U*A* (SEQ ID NO:13) U*U,A*A*U*A*A*U*A*A*U*A*A*U*A*A*U*A*A*U* (SEQ ID NO:16) A*A,A*A*A*U*A*A*A*U*A*A*A*U*A*A*A*U*A*A* (SEQ ID NO:17) A*U,A*A*A*A*U*A*A*A*A*U*A*A*A*A*U*A*A*A* (SEQ ID NO:18) A*U,C*U*A*C*U*A*C*U*A*C*U*A*C*U*A*C*U*A* (SEQ ID NO:24) C*U, U*U*A*U*U*A*U,(SEQ ID NO:30) U*A*U*A*U*A*U, (SEQ ID NO:33)C*C*G*A*G*C*C*G*C*A*U*U*A*C*C*C, (SEQ ID NO:48)C*C*G*A*G*C*C*G*A*U*U*G*A*A*C*C, (SEQ ID NO:76)C*C*G*A*G*C*C*G*A*A*U*A*C*C*C*C, (SEQ ID NO:42)C*C*G*A*G*C*C*A*U*A*U*A*U*A*U*C, (SEQ ID NO:39)C*C*G*A*G*C*C*G*A*U*A*U*U*A*C*C, (SEQ ID NO:65)C*C*G*A*G*C*C*G*A*A*U*C*C*C*C*C, (SEQ ID NO:44)C*C*G*A*G*C*C*G*C*C*U*A*C*C*C*C, (SEQ ID NO:47)C*C*G*A*G*C*C*A*U*A*U*A*U*C*C*C, (SEQ ID NO:38)C*C*G*A*G*C*C*G*C*U*A*U*A*C*C*C, (SEQ ID NO:37)C*C*G*A*G*C*C*G*A*A*U*A*A*C*C*C, (SEQ ID NO:40)C*C*G*A*G*C*C*G*C*U*A*U*C*C*C*C, (SEQ ID NO:55)C*C*G*A*G*C*C*G*A*A*G*G*U*A*C*C, (SEQ ID NO:82)C*C*G*A*G*C*C*G*A*A*G*A*U*A*C*C, (SEQ ID NO:85)C*C*G*A*G*C*C*G*A*A*U*G*U*A*C*C, (SEQ ID NO:63)C*C*G*A*G*C*C*G*C*C*U*A*A*C*C*C, (SEQ ID NO:43)C*C*G*A*G*C*C*G*C*A*U*A*U*C*C*C, (SEQ ID NO:36)C*C*G*A*G*C*C*G*A*A*G*C*U*A*C*C, (SEQ ID NO:87)C*C*G*A*G*C*C*G*C*A*U*A*C*C*C*C, (SEQ ID NO:45)C*C*G*A*G*C*C*G*C*A*U*A*A*C*C*C, (SEQ ID NO:41)C*C*G*A*G*C*C*G*A*A*G*G*U*G*C*C, (SEQ ID NO:83)C*C*G*A*G*C*C*G*C*A*U*C*C*C*C*C, (SEQ ID NO:46)C*C*G*A*G*C*C*G*A*A*G*C*U*G*C*C, (SEQ ID NO:88)C*C*G*A*G*C*C*G*C*C*G*C*C*C*C*C, (SEQ ID NO:35)C*C*G*A*G*C*C*G*A*A*G*C*U*C*C*C, (SEQ ID NO:84) orC*C*G*A*G*C*C*G*A*A*G*G*C*A*C*C. (SEQ ID NO:56)

The ORN specifically excludes TLR7/8 motifs. A TLR7/8 motif may includefor example a ribonucleotide sequence selected from (i)5′-C/U-U-G/U-U-3′, (ii) 5′-R-U-R-G-Y-3′, (iii) 5′-G-U-U-G-B-3′, (iv)5′-G-U-G-U-G/U-3′, and (v) 5′-G/C-U-A/C-G-G-C-A-C-3′,wherein C/U is cytosine (C) or uracil (U), G/U is guanine (G) or U, R ispurine, Y is pyrimidine, B is U, G, or C, G/C is G or C, and A/C isadenine (A) or C.

In various embodiments 5′-C/U-U-G/U-U-3′ is CUGU, CUUU, UUGU, or UUUU.

In various embodiments 5′-R-U-R-G-Y-3′ is GUAGU, GUAGC, GUGGU, GUGGC,AUAGU, AUAGC, AUGGU, or AUGGC. In one embodiment the base sequence isGUAGUGU.

In various embodiments 5′-G-U-U-G-B-3′ is GUUGU, GUUGG, or GUUGC.

In various embodiments 5′-G-U-G-U-G/U-3′ is GUGUG or GUGUU. In oneembodiment the base sequence is GUGUUUAC.

In various embodiments 5′-G/C-U-A/C-G-G-C-A-C-3′ is GUAGGCAC, GUCGGCAC,CUAGGCAC, or CUCGGCAC.

In one aspect the invention provides an immunostimulatory compositionincluding an immunostimulatory ORN of the invention and an adjuvant. Invarious embodiments the adjuvant is an adjuvant that creates a depoteffect, an immune-stimulating adjuvant, or an adjuvant that creates adepot effect and stimulates the immune system. In one embodiment theimmunostimulatory composition according to this aspect of the inventionis a conjugate of the immunostimulatory ORN and the adjuvant. In oneembodiment according to this aspect of the invention theimmunostimulatory ORN is covalently linked to the adjuvant. In otherembodiments they are not conjugated. In one embodiment the adjuvant isan agonist of TLR9. In one embodiment the adjuvant is animmunostimulatory CpG nucleic acid.

The compositions of the invention can optionally include an antigen.Thus in one aspect the invention provides a vaccine, wherein the vaccineincludes an immunostimulatory ORN of the invention and an antigen. Inone aspect the invention provides a vaccine that includes a conjugate ofan immunostimulatory ORN of the invention and an antigen. In oneembodiment the conjugate according to this aspect of the inventionincludes the immunostimulatory ORN covalently linked to the antigen. Inother embodiments they are not conjugated. In various embodiments theantigen can be an antigen per se. The antigen can be any antigen,including a cancer antigen, a microbial antigen, or an allergen.

In one aspect the invention provides an immunostimulatory compositionincluding a conjugate of an immunostimulatory ORN of the invention and alipophilic moiety. In one embodiment the immunostimulatory ORN iscovalently linked to the lipophilic moiety. In one embodiment thelipophilic moiety is selected from the group consisting of cholesteryl,palmityl, and fatty acyl. In one embodiment the lipophilic moiety is aderivative of cholesterol, e.g., cholesteryl.

In one embodiment the immunostimulatory ORN includes at least onedeoxyribonucleotide. The at least one deoxyribonucleotide generally canoccur anywhere outside of the immunostimulatory RNA motif. In variousembodiments the at least one deoxyribonucleotide is 1, 2, 3, 4, 5, 6, 7,8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, or 24consecutive deoxyribonucleotides. Immunostimulatory ORN includingnonconsecutive deoxyribonucleotides are also contemplated by theinvention. In various embodiment the at least one deoxyribonucleotide isa 5′ end, a 3′ end, or both a 5′ end and a 3′ end of theimmunostimulatory ORN. The at least one deoxyribonucleotide alsocorresponds to a DNA portion of a chimeric DNA:RNA molecule. In oneembodiment a DNA component of the chimeric DNA:RNA molecule includes aCpG nucleic acid, i.e., a TLR9 agonist. In one embodiment the DNA andRNA portions of the chimeric DNA:RNA molecule are covalently linkedthrough an internucleotide phosphate bond. In another embodiment the DNAand RNA portions of the chimeric DNA:RNA molecule are covalently linkedthrough a linker, e.g., a non-nucleotidic linker.

In one aspect the invention provides an immunostimulatory compositionthat includes a covalently closed, partially single-stranded,dumbbell-shaped nucleic acid molecule, wherein at least onesingle-stranded portion of the molecule includes an immunostimulatoryRNA motif of the invention.

In one aspect the invention provides a pharmaceutical compositionincluding the composition of any of the foregoing aspects of theinvention, in association with a delivery vehicle chosen from a cationiclipid, a liposome, a cochleate, a virosome, an immune-stimulatingcomplex (ISCOM), a microparticle, a microsphere, a nanosphere, aunilamellar vesicle (LUV), a multilamellar vesicle, an oil-in-wateremulsion, a water-in-oil emulsion, an emulsome, and a polycationicpeptide, and, optionally, a pharmaceutically acceptable carrier. In oneembodiment according to this aspect of the invention the pharmaceuticalcomposition includes an antigen.

The ORN may be formulated in a nebulizer or an inhaler, such as ametered dose inhaler or a powder inhaler. In some embodiments the ORNfurther includes an additional composition such as a chemotherapeuticagent, an anti-viral agent or a pharmaceutically acceptable carrier. Thepharmaceutically acceptable carrier may be formulated for injection ormucosal administration.

Further according to these and other aspects of the invention, invarious embodiments the immunostimulatory ORN can optionally include atleast one 5′-5′ internucleotide linkage, at least one 3′-3′internucleotide linkage, at least one 5′-5′ internucleotide linkage thatincludes a linker moiety, at least one 3′-3′ internucleotide linkagethat includes a linker moiety, or any combination thereof. The linkermoiety in one embodiment is a non-nucleotidic linker moiety.

Further still according to these and other aspects of the invention, invarious embodiments the immunostimulatory ORN can optionally include atleast one 2′-2′ internucleotide linkage, at least one 2′-3′internucleotide linkage, at least 2′-5′ internucleotide linkage, or anycombination thereof. In a preferred embodiment the at least one 2′-2′internucleotide linkage, at least one 2′-3′ internucleotide linkage, orat least 2′-5′ internucleotide linkage occurs outside of theimmunostimulatory RNA motif.

Also according to these and other aspects of the invention, theimmunostimulatory ORN in one embodiment includes at least one multiplierunit. Accordingly, in certain embodiments the immunostimulatory ORN ofthe invention can have a branched structure. Branched compositions caninclude 3′-5′,5′-5′,3′-3′,2′-2′,2′-3′, or 2′-5′ internucleotidelinkages, in any combination. In one embodiment the immunostimulatoryORN includes at least two multiplier units, resulting in a so-calleddendrimer. In addition, in certain embodiments the immunostimulatory ORNof the invention may include two or more immunostimulatory RNA motifs,arranged for example in tandem along a linear ORN, on different arms ofa branched structure, or both in tandem along a linear ORN and ondifferent arms of a branched structure. Branched structures, includingdendrimers, can optionally include at least one immunostimulatory CpGnucleic acid, for example as a separate arm of a branched structure.

Further according to these and other aspects of the invention, in oneembodiment the immunostimulatory ORN does not include a CG DNA or RNAdinucleotide.

In one aspect the invention provides a method for down-regulatingimmunosuppressive CD4+ regulatory (Treg) cells. The method according tothis aspect of the invention includes the step of contacting a CD4+ Tregcell with a composition containing a TLR8-specific immunostimulatory ORNof the invention in an effective amount to reduce the inhibitory effectof the CD4+ Treg cell. In one embodiment the composition includes aTLR8-specific ORN and an immunostimulatory CpG nucleic acid, wherein theTLR8-specific ORN and the immunostimulatory CpG nucleic acid are notlinked. In one embodiment the composition includes a TLR8-specific ORNand an immunostimulatory CpG nucleic acid, wherein the TLR8-specific ORNand the immunostimulatory CpG nucleic acid are present as a conjugate.

In another aspect the invention provides a method for modulating animmune response in a subject The method according to this aspect of theinvention includes the step of administering to a subject an effectiveamount of a composition of the invention. In some embodiments the ORNmay be delivered to the subject to treat autoimmune disease or airwayremodeling in the subject. The ORN may be administered with or withoutan antigen to the subject. Optionally the ORN is delivered by a routesuch as oral, nasal, sublingual, intravenous, subcutaneous, mucosal,respiratory, direct injection, and dermally. The ORN may be delivered tothe subject in an effective amount to induce cytokine expression, suchas TNFα, IL-10, IL-6, IFN-γ, MCP1, and IL-12.

In one aspect the invention provides a method of vaccinating a subject.The method according to this aspect of the invention includes the stepof administering to the subject an antigen and an immunostimulatory ORNof the invention.

In one aspect the invention provides a method for treating a subjecthaving or at risk of having an infectious disease. The method accordingto this aspect of the invention includes the step of administering tothe subject an effective amount of a composition of the invention. Inone embodiment the method includes the step of administering to thesubject an effective amount of an immunostimulatory ORN of theinvention. In one embodiment the subject has a viral infection. Theviral infection may be, for example, hepatitis B or hepatitis C. Ananti-viral agent may be also administered to the subject. Optionally theanti-viral agent is linked to the ORN.

In one aspect the invention provides a method for treating a subjecthaving or at risk of having a cancer. The method according to thisaspect of the invention includes the step of administering to thesubject an effective amount of a composition of the invention. In oneembodiment the method includes the step of administering to the subjectan effective amount of an immunostimulatory ORN of the invention. In oneembodiment a chemotherapeutic or radiation is also administered to thesubject.

In one aspect the invention provides a method for treating a subjecthaving or at risk of having a cancer. The method according to thisaspect of the invention includes the step of administering to thesubject an effective amount of a composition containing a TLR8-specificimmunostimulatory ORN of the invention to reduce the inhibitory effectof CD4+ Treg cells. In one embodiment the composition includes aTLR8-specific ORN and an immunostimulatory CpG nucleic acid, wherein theTLR8-specific ORN and the immunostimulatory CpG nucleic acid are notlinked. In one embodiment the composition includes a TLR8-specific ORNand an immunostimulatory CpG nucleic acid, wherein the TLR8-specific ORNand the immunostimulatory CpG nucleic acid are present as a conjugate.

In one aspect the invention provides a method for treating a subjecthaving or at risk of having an allergic condition. The method accordingto this aspect of the invention includes the step of administering tothe subject an effective amount of a composition of the invention. Inone embodiment the method includes the step of administering to thesubject an effective amount of an immunostimulatory ORN of theinvention. In one embodiment the subject has allergic rhinitis.

In one aspect the invention provides a method for treating a subjecthaving or at risk of having asthma. The method according to this aspectof the invention includes the step of administering to the subject aneffective amount of a composition of the invention. In one embodimentthe method includes the step of administering to the subject aneffective amount of an immunostimulatory ORN of the invention. In oneembodiment the asthma is asthma exacerbated by viral infection. The ORNmay be administered with or without an allergen.

In another aspect the invention provides a method for treating a subjecthaving airway remodeling. The method according to this aspect of theinvention includes the step of administering to the subject an effectiveamount of an immunostimulatory ORN of the invention.

In one aspect the invention provides a method for increasingantibody-dependent cellular cytotoxicity (ADCC). The method according tothis aspect of the invention includes the step of administering to asubject in need of increased ADCC an effective amount of animmunostimulatory ORN of the invention and an antibody to increase ADCC.In one embodiment the antibody is an antibody specific for a cancerantigen or other antigen expressed by a cancer cell. In one embodimentthe antibody is an IgG antibody.

The invention in one aspect provides a method for enhancing epitopespreading. The method according to this aspect of the invention includesthe sequential steps of contacting a cell of the immune system with anantigen and subsequently contacting the cell with at least two doses ofan immunostimulatory ORN of the invention. In one embodiment the methodis performed in vivo. The method in one embodiment includes the steps ofadministering to a subject a vaccine that includes an antigen and anadjuvant and subsequently administering to the subject at least twodoses of an immunostimulatory ORN of the invention, in an effectiveamount to induce multiple epitope-specific immune responses. The methodin one embodiment involves applying a therapeutic protocol which resultsin immune system antigen exposure in a subject, followed byadministering at least two doses of an immunostimulatory ORN of theinvention, in an effective amount to induce multiple epitope-specificimmune responses. In various embodiments the therapeutic protocol issurgery, radiation, chemotherapy, other cancer medicaments, a vaccine,or a cancer vaccine. In one embodiment the at least two doses of theimmunostimulatory ORN are administered at least one day to one weekapart from one another. In one embodiment the at least two doses of theimmunostimulatory ORN are administered at least one week to one monthapart from one another. In one embodiment the at least two doses of theimmunostimulatory ORN are administered at least one month to six monthsapart from one another.

In one aspect the invention is a method for stimulating production of apro-inflammatory cytokine, by contacting a TLR8 expressing cell with anRNA oligonucleotide (ORN) comprising: N-U-R₁-R₂, wherein N is aribonucleotide and N does not include a U, U is Uracil or a derivativethereof, and R is a ribonucleotide wherein at least one of R₁ and R₂ isAdenosine (A) or Cytosine or derivatives thereof and wherein R is not Uunless N-U-R₁-R₂ includes at least two A, wherein the ORN does notinclude a TLR7/8 motif and wherein the ORN is 4-100 in length, in aneffective amount to stimulate pro-inflammatory cytokine production andwherein IFN-α production in response to the ORN is not inducedsignificantly relative to background. In some embodiments the IFN-αproduction in response to the ORN is less than 300 pg/ml. In oneembodiment the ORN is not ACCCAUCUAUUAUAUAACUC (SEQ ID NO:89). The ORNmay or may not be complexed toN-[1-(2,3-Dioleoyloxy)propyl]-N,N,Ntrimethylammoniummethyl-sulfate(DOTAP).

In some embodiments the TLR8 expressing cell is a monocyte or a mDC. Inyet other embodiments the TLR8 expressing cell is in vitro or in vivo.

These and other features of the invention will be described in furtherdetail in connection with the detailed description of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a set of graphs depicting ORN induced cytokine production uponPBMC stimulation. By measuring IFN-alpha and TNF-alpha cytokineproduction differences between TLR8 and TLR7/8 motifs were seen. HumanPBMC were stimulated with the indicated ORN (2 μM with 1/3 dilution)complexed to DOTAP (25 μg/ml 1/3 dilution) or with R-848 (2 μM with 1/3dilution) in a full titration curve. After 16 h supernatants wereharvested and IFN-alpha (FIG. 1 a) and TNF-alpha (FIG. 1 b) weremeasured by ELISA. Data show the mean of three blood donors of a leastthree independent experiments. DOTAP alone did not show an effect. TheORN are complexed to DOTAP, R-848 is not complexed. DOTAP alone is acontrol. In FIG. 1 c human PBMC were stimulated with 0.2 μM of theindicated ORN complexed to DOTAP (2.2 μg/ml) or with R-848 (2 μM). After16 h supernatants were harvested and IFN-alpha (left panel) andTNF-alpha (right panel) were measured by ELISA. Data shown are mean(±SEM) of 3 donors.

FIG. 2 is a set of bar graphs depicting ORN induced cytokine productionupon isolated pDC (FIG. 2 a), monocytes (FIG. 2 b) and mDC (FIG. 2 c)stimulation. Cells were stimulated with 0.5 μM ORN complexed to 10 μg/mlDOTAP, 0.5 μM CpG ODN or DOTAP or media alone and IFN-alpha (FIG. 2 a),TNF-alpha (FIG. 2 c) and IL-12p40 (FIG. 2 c) were measured.

FIG. 3 is a set of bar graphs depicting ORN induced cytokine productionupon PBMC stimulation. Human PBMC were stimulated with the indicated ORN(0.5 μM ORN) complexed to 10 μg/ml DOTAP and IFN-alpha (FIG. 3A) andTNF-alpha (FIG. 3B) were measured and cytokine production was measuredby the ELISA technique and Luminex technique compared.

FIG. 4 is a bar graph demonstrating a comparison of IFN-alpha (FIG. 4 a)and TNF-alpha (FIG. 4 b) max activities of the indicated ORN. Human PBMCwere stimulated with ORN (7 concentrations, starting from 2 μM with 1/3dilution) complexed to DOTAP (starting from 25 μg/ml with 1/3 dilutions)and Mean Max activities at 0.6 μM of 3-6 Blood Donors in two individualexperiments were assessed.

FIG. 5 is a bar graph demonstrating a comparison of IFN-alpha maxactivity (FIG. 5 a) to IFN-alpha EC50 (FIG. 5 b). Human PBMC werestimulated with ORN complexed to DOTAP and IFN-alpha was measured.

FIG. 6 is a set of graphs comparing titration curves for ORN with TLR8(SEQ ID NO:13) or TLR7/8 (SEQ ID NO:21) for PBMC, isolated pDC orisolated monocytes of 3 Blood Donors. The cells were stimulated with ORN(4 concentrations, starting from 1 μM with 1/4 dilution) complexed toDOTAP (starting from 25 μg/ml with 1/4 dilutions). After 16 hours thesupernatents were harvested and cytokine production measured by Luminextechnologies. The graphs show the percent SEQ ID NO:21 (at 0.3 μM)cytokine production.

FIG. 7 shows a set of bar graphs demonstrating the mean max activitiesat any concentration of 3 Blood Donors for PBMC, isolated monocytes,isolated pDC and CD14-CD123− PBMC. The cells were stimulated with ORN (4concentrations, starting from 1 μM with 1/4 dilution) complexed to DOTAP(starting from 25 μg/ml with 1/4 dilutions). After 16 hours thesupernatents were harvested and cytokine production measured by Luminextechnology. Red squared indicated positive reactions over background ofDOTAP and media.

FIG. 8 is a set of bar graphs showing differences between TLR8 (SEQ IDNO:13) and TLR7/8 (SEQ ID NO:21) ORN. The cells were stimulated with ORN(4 concentrations, starting from 1 μM with 1/4 dilution) complexed toDOTAP (starting from 25 μg/ml with 1/4 dilutions). After 16 hours thesupernatants were harvested and cytokine production measured by Luminextechnology. The graphic showed the measured mean max at anyconcentration cytokine production as percent of the TLR8 ORN (SEQ IDNO:13) to the TLR7/8 ORN (SEQ ID NO:21). This is shown for isolated pDC,PBMC, isolated monocytes and CD123-CD14− PBMC.

FIG. 9 is a set of bar graphs and curves that shows reaction of TLR8 ORN(SEQ ID NO:13) and TLR7/8 ORN (SEQ ID NO:21) acting via TLR8 withinstable-transfected HEK-293 cells. Stable-transfected HEK-293 cells withNFκB-luciferase read out reporter and human TLR8 were stimulated for 16hours with indicated ORN. After 16 hours the supernatants were removed,the cells lysed and the luciferase activity or cytokine level wasmeasured. FIGS. 9 a and 9 b show fold induction of NFκB-luciferase afterstimulus. FIG. 9 c shows fold induction of NFκB-luciferase afterstimulus in the presence of inhibitors. FIG. 9 d shows stimulation ofIP-10 after stimulus as measured by luciferase assay.

FIG. 10 is a series of graphs showing surface marker expression uponhuman pDC stimulation with AU-rich or GU-rich ORN. CD123+purified pDC(FIGS. 10 a and 10 b) or isolated monocytes (FIG. 10 c) were incubatedwith 1 μM ORN complexed to 25 μg/ml DOTAP or DOTAP alone (FIG. 10 a) orindicated amounts of ORN complexed to DOTAP or DOTAP alone (FIGS. 10b-10 c). After 16 h cells were harvested and stained with CD123, CD11cand HLA-DR antibodies (FIGS. 10 a and 10 b) or CD14 and CD19 (FIG. 10c). Cell surface marker activation was measured by CD86 (FIGS. 10 a and10 b) or CD80 (FIG. 10 c) expression. FIG. 10 a shows FACS analysisdemonstrating that AU-rich ORN (SEQ ID NO:13) and GU-rich ORN (SEQ IDNO:21) show differences in CD86 surface marker expression upon pDCstimulation. FIG. 10 b is a graph illustrating that CD86 surface markerexpression upon human pDC stimulation is dose-dependent. FIG. 10 c is agraph showing that AU-rich ORN (SEQ ID NO:13) and GU-rich ORN (SEQ IDNO:21) show no difference in CD80 surface marker expression upon humanPBMC (data not shown) and CD14-positive cell stimulation.

FIG. 11 is a set of bar graphs showing differences between TLR8 ORN (SEQID NO:13) and TLR7/8 ORN (SEQ ID NO:21). SEQ ID NO:5 ORN was used as acontrol. Bovine PBMC were incubated with either 10 μg/ml ORN (HD) or 2.5μg/ml ORN (LD) for 48 hours. Supernatants were collected and analyzed byELISA. FIGS. 11 a-c show the level of IL-12, IFN-γ, and TNF-alpha,respectively.

FIG. 12 is a series of graphs demonstrating that murine cells do notrespond to AU-rich ORN SEQ ID NO:13 in vivo or in vitro. Cells used weremouse macrophage cell line Raw264.7 cells (FIG. 12 a), J774 cells (FIG.12 b), purified mouse CD11c+ cells (sv129 mice) (FIGS. 12 c-12 g) andmouse cells in vivo. Cytokine concentration was evaluated by ELISA.

FIG. 13 is a graph demonstrating that rat splenocytes do not respond toAU-rich ORN SEQ ID NO:13. Splenocytes from 3 Sprague-Dawley rats werepooled and stimulated with indicated concentrations of SEQ ID NO:21, SEQID NO:13 (both complexed to 62.5 μg/ml DOTAP with 1/5 dilution), R-848or DOTAP alone (62.5 μg/ml->1/5 dilution). Supernatants were harvestedafter 20 hours and TNF-alpha levels were measured by ELISA.

DETAILED DESCRIPTION OF THE INVENTION

The invention relates in part to the discovery by the inventors of anumber of sequence-specific immunostimulatory RNA motifs. It has nowbeen discovered that molecules containing an immunostimulatory RNA motifare, alone or in combination with certain other components, importantimmunostimulatory compounds that find use in a number of methods fortreating subjects having or at risk of having a condition in which itwould be advantageous to induce, augment, or redirect an immuneresponse. As used herein, in one embodiment an immunostimulatorycomposition of the invention is an immunostimulatory ORN of theinvention.

It has been discovered that certain sequence-specific RNA motifs areimmunostimulatory, acting through TLR8, as opposed to other motifs (GUrich and CU rich) that act on TLR 7 and TLR8. RNA Oligonucleotides(ORN), preferably containing AU-rich sequences, stimulate an immuneresponse through TLR8. Differences between IFN-alpha, TNF-alpha,IFN-gamma and IL-12 production have been observed in these distinctclasses of ORN, e.g. ORN containing AU- and GU-containing repetitions.Interestingly, the immunostimulatory ORN of the invention have beenfound to produce a strong pro-inflammatory cytokine response, with theexception of IFN-alpha and IFN-alpha related molecules. IFN-alphaproduction is diminished or lacking upon stimulation with these novelORN.

The immunostimulatory RNA motif according to some aspects of theinvention is N-U-R₁-R₂.

N is a ribonucleotide and N does not include a U. In some embodiments Nis Adenosine or Cytosine (C) or derivatives thereof.

U is Uracil or a derivative thereof.

R is a ribonucleotide wherein at least one of R₁ and R₂ is Adenosine (A)or Cytosine or derivatives thereof. R is not U unless N-U-R₁-R₂ includesat least two A.

The ORN of the invention includes at least one and in some embodimentsmore than one (i.e., 2, 3, or 4) immunostimulatory motifs, N-U-R₁-R₂.The ORN does not include a TLR7/8 motif.

The ORN is an oligonucleotide. Optionally, the oligonucleotide is 4-100in length. The ORN may also be, for instance, 8-40, 15-25 or 20-30nucleotides in length. Optionally the ORN includes at least one backbonemodification.

N-U-R₁-R₂ may in some embodiments include at least 3 As or at least 2Cs. Optionally, N-U-R₁-R₂ includes at least one G or C.

In some embodiments the ORN is not ACCCAUCUAUUAUAUAACUC (SEQ ID NO:89).

The ORN may further comprise a pharmaceutically acceptable carrier whichoptionally is a lipid carrier such asN-[1-(2,3-Dioleoyloxy)propyl]-N,N,Ntrimethylammoniummethyl-sulfate(DOTAP). In other embodiments the ORN is not complexed to DOTAP. Inother embodiments the pharmaceutically acceptable carrier may be apeptide such as a polycationic peptide. Polycationic peptides include,for instance, multiple poly-lysines, poly-arginines and poly-peptidescontaining more than 50% of basic amino acids, especially arginine orlysine residues, in a range of more than 5, especially more than 8 aminoacid residues or mixtures thereof and may, for instance, includederivatives of a naturally occurring insect antimicrobial proteins.

In other embodiments the ORN includes at least one AU.

In addition to being sequence-specific, the immunostimulatory RNA motifsare effective as single-stranded RNA, partially double-stranded RNA, orwholly double-stranded RNA.

Clear differences between production of IFN-alpha and IFN-alpha relatedmolecules and other pro-inflammatory cytokines such as TNF-alpha,IFN-gamma, IL-10, IL-6 and IL-12 were observed for ORN of the inventionand ORN having a TLR7/8 motif, i.e. GU-containing repetitions. The ORNof the invention having a N-U-R₁-R₂ motif, for example those containingAU or AUU repetitions (SEQ ID NO:12, SEQ ID NO:13) revealed no IFN-alphacytokine production upon PBMC and pDC stimulation. In contrast ORNhaving three and more U in a row (SEQ ID NO:14, SEQ ID NO:15) inducedIFN-alpha production, despite the presence of As. Interestingly, usingthe same set of ORN but with G exchanged for A strong IFN-alphaproduction upon PBMC stimulation was observed. The data presented hereinstrongly suggest the existence of two different ORN classes: one actingon cells expressing TLR8 such as monocytes and mDCs (SEQ ID NO:12, SEQID NO:13, SEQ ID NO:16-SEQ ID NO:18), the ORN containing N-U-R₁-R₂motifs of the invention and another one acting on cells expressing bothTLR7/8 such as monocytes, mDCs and pDCs (SEQ ID NO:14, SEQ ID NO:15, SEQID NO:19-SEQ ID NO:23) containing CU, GU and GUU sequences.

Thus, the ORN of the invention have the ability to induce an immuneresponse without inducing significant amounts of IFN-alpha or IFN-alpharelated molecules relative to background. A significant amount ofIFN-alpha or IFN-alpha related molecules relative to background ispreferably less than 20% change in levels of IFN-alpha or IFN-alpharelated molecules relative to background. In some embodiments it is lessthan 15%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, or 1%. In otherembodiments the amount of IFN-alpha or related molecules that is inducedis equivalent to background or less than background levels. In yet otherembodiments the amount of IFN-alpha induced by the ORN of the inventionis less than or equal to 20% of the IFN-alpha induced by a TLR7/8 ORN.The amount of IFN-alpha induced by the ORN of the invention mayoptionally be less than 300 pg/ml in an in vitro assay or may have anEC50 of greater than 1.5 μM.

An IFN-alpha related molecule, as used herein, is a cytokine or factorthat is related to the expression of IFN-alpha. These molecules includebut are not limited to MIP1-beta, IP-10 and MIP1-alpha.

It was recently reported that CD4+ Treg cells express TLR8 and that TLR8signaling in these cells reduces or reverses their immunoinhibitoryfunction. Peng G et al. (2005) Science 309:1380-4. Increased populationsof CD4+ Treg cells have been observed in patients with various types ofcancers, where immunosuppression may contribute to the immune “escape”and unregulated growth of these cancers. Reversal of Treg-mediatedsuppression thus would be expected to be beneficial in treating cancer.

The ORN specifically exclude TLR7/8 motifs. It has been discovered thatTLR7/8 motifs can produce dominant results that mask the uniqueimmunostimulatory properties of the ORN of the invention. A TLR7/8 motifmay include, for example, a ribonucleotide sequence such as5′-C/U-U-G/U-U-3′,5′-R-U-R-G-Y-3′,5′-G-U-U-G-B-3′, 5′-G-U-G-U-G/U-3′, or5′-G/C-U-A/C-G-G-C-A-C-3′. C/U is cytosine (C) or uracil (U), G/U isguanine (G) or U, R is purine, Y is pyrimidine, B is U, G, or C, G/C isG or C, and A/C is adenine (A) or C. The 5′-C/U-U-G/U-U-3′ may be CUGU,CUUU, UUGU, or UUUU. In various embodiments 5′-R-U-R-G-Y-3′ is GUAGU,GUAGC, GUGGU, GUGGC, AUAGU, AUAGC, AUGGU, or AUGGC. In one embodimentthe base sequence is GUAGUGU. In various embodiments 5′-G-U-U-G-B-3′ isGUUGU, GUUGG, or GUUGC. In various embodiments 5′-G-U-G-U-G/U-3′ isGUGUG or GUGUU. In one embodiment the base sequence is GUGUUUAC. Invarious other embodiments 5′-G/C-U-A/C-G-G-C-A-C-3′ is GUAGGCAC,GUCGGCAC, CUAGGCAC, or CUCGGCAC.

The invention relates generally to immunostimulatoryoligoribonucleotides that include one or more immunostimulatory RNAmotifs, immunostimulatory compositions containing one or moreimmunostimulatory ORN of the invention, and methods for use of theimmunostimulatory ORN and immunostimulatory compositions of theinvention.

As used herein, the terms “RNA” and equivalently “natural RNA” shallrefer to two or more ribonucleotides (i.e., molecules each comprising aribose sugar linked to a phosphate group and to a purine or pyrimidinenucleobase (e.g., guanine, adenine, cytosine, or uracil)) covalentlylinked together by 3′-5′ phosphodiester linkage(s).

The immunostimulatory RNA motif can occur at an end of theimmunostimulatory ORN (when the immunostimulatory ORN has free ends).For example, an immunostimulatory ORN with free ends and theimmunostimulatory RNA motif positioned at an end of theimmunostimulatory ORN can be represented as X_(a)M or as MX_(b), where Mrepresents the immunostimulatory RNA motif and each of X_(a) and X_(b)independently represents one or more identical or nonidenticalnucleotides of the immunostimulatory ORN exclusive of theimmunostimulatory RNA motif.

Alternatively, the immunostimulatory RNA motif can be flanked on both ofits ends by at least one additional nucleotide of the immunostimulatoryORN, whether the immunostimulatory ORN has free ends or not. Forexample, an immunostimulatory ORN with free ends and nucleotidesflanking the immunostimulatory RNA motif can be represented asX_(a)MX_(b), where M represents the immunostimulatory RNA motif and eachof X_(a) and X_(b) independently represents one or more identical ornonidentical nucleotides of the immunostimulatory ORN exclusive of theimmunostimulatory RNA motif.

In different embodiments the immunostimulatory ORN including theimmunostimulatory RNA motif can include a single motif or more than oneimmunostimulatory RNA motif. It is believed that there may be anadvantage to having two or more immunostimulatory RNA motifs in a singleimmunostimulatory ORN, for example if the motifs are spaced such thatthe immunostimulatory ORN can engage two or more TLRs. For example, theimmunostimulatory ORN could engage two or more TLR8 receptors therebyamplifying or modifying the resulting immunostimulatory effect.

When the immunostimulatory ORN includes more than one immunostimulatoryRNA motif, the immunostimulatory ORN can be represented in oneembodiment as M₁XM₂, wherein M₁ and M₂ each independently represent animmunostimulatory RNA motif and X represents one or more identical ornonidentical nucleotides of the immunostimulatory ORN exclusive of theimmunostimulatory RNA motifs. In one embodiment X includes anon-nucleotidic linker as described herein. In one embodiment X includesa branching unit as described herein.

When there is more than one immunostimulatory RNA motif in theimmunostimulatory ORN, the motifs generally can occur at any positionalong the immunostimulatory ORN. For example, when there are two motifs,they may each occur at an end of the immunostimulatory ORN.Alternatively, one motif can occur at an end and one motif can beflanked on both of its ends by at least one additional nucleotide of theimmunostimulatory ORN. In yet another embodiment each motif can beflanked on both of its ends by at least one additional nucleotide of theimmunostimulatory ORN.

Immunostimulatory ORN include, but are not limited to the following,shown 5′ to 3′ reading left to right:

In some embodiments the ORN is one of the active ORN shown in Tables 1and 2 below, such as the following: U*U*A*G*G*C*A*C (SEQ ID NO:2),A*U*A*G*G*C*A*C, (SEQ ID NO:4) G*C*C*A*C*C*G*A*G*C*C*G*A*A*U*A*U*A* (SEQID NO:11) C*C, A*U*A*U*A*U*A*U*A*U*A*U*A*U*A*U*A*U* (SEQ ID NO:12) A*U,U*U*A*U*U*A*U*U*A*U*U*A*U*U*A*U*U*A* (SEQ ID NO:13) U*U,A*A*U*A*A*U*A*A*U*A*A*U*A*A*U*A*A*U* (SEQ ID NO:16) A*A,A*A*A*U*A*A*A*U*A*A*A*U*A*A*A*U*A*A* (SEQ ID NO:17) A*U,A*A*A*A*U*A*A*A*A*U*A*A*A*A*U*A*A*A* (SEQ ID NO:18) A*U,C*U*A*C*U*A*C*U*A*C*U*A*C*U*A*C*U*A* (SEQ ID NO:24) C*U, U*U*A*U*U*A*U,(SEQ ID NO:30) U*A*U*A*U*A*U, (SEQ ID NO:33)C*C*G*A*G*C*C*G*C*A*U*U*A*C*C*C, (SEQ ID NO:48)C*C*G*A*G*C*C*G*A*U*U*G*A*A*C*C, (SEQ ID NO:76)C*C*G*A*G*C*C*G*A*A*U*A*C*C*C*C, (SEQ ID NO:42)C*C*G*A*G*C*C*A*U*A*U*A*U*A*U*C, (SEQ ID NO:39)C*C*G*A*G*C*C*G*A*U*A*U*U*A*C*C, (SEQ ID NO:65)C*C*G*A*G*C*C*G*A*A*U*C*C*C*C*C, (SEQ ID NO:44)C*C*G*A*G*C*C*G*C*C*U*A*C*C*C*C, (SEQ ID NO:47)C*C*G*A*G*C*C*A*U*A*U*A*U*C*C*C, (SEQ ID NO:38)C*C*G*A*G*C*C*G*C*U*A*U*A*C*C*C, (SEQ ID NO:37)C*C*G*A*G*C*C*G*A*A*U*A*A*C*C*C, (SEQ ID NO:40)C*C*G*A*G*C*C*G*C*U*A*U*C*C*C*C, (SEQ ID NO:55)C*C*G*A*G*C*C*G*A*A*G*G*U*A*C*C, (SEQ ID NO:82)C*C*G*A*G*C*C*G*A*A*G*A*U*A*C*C, (SEQ ID NO:85)C*C*G*A*G*C*C*G*A*A*U*G*U*A*C*C, (SEQ ID NO:63)C*C*G*A*G*C*C*G*C*C*U*A*A*C*C*C, (SEQ ID NO:43)C*C*G*A*G*C*C*G*C*A*U*A*U*C*C*C, (SEQ ID NO:36)C*C*G*A*G*C*C*G*A*A*G*C*U*A*C*C, (SEQ ID NO:87)C*C*G*A*G*C*C*G*C*A*U*A*C*C*C*C, (SEQ ID NO:45)C*C*G*A*G*C*C*G*C*A*U*A*A*C*C*C, (SEQ ID NO:41)C*C*G*A*G*C*C*G*A*A*G*G*U*G*C*C, (SEQ ID NO:83)C*C*G*A*G*C*C*G*C*A*U*C*C*C*C*C, (SEQ ID NO:46)C*C*G*A*G*C*C*G*A*A*G*C*U*G*C*C, (SEQ ID NO:88)C*C*G*A*G*C*C*G*C*C*G*C*C*C*C*C, (SEQ ID NO:35)C*C*G*A*G*C*C*G*A*A*G*C*U*C*C*C, (SEQ ID NO:84) orC*C*G*A*G*C*C*G*A*A*G*G*C*A*C*C. (SEQ ID NO:56)

As mentioned above, RNA is a polymer of ribonucleotides joined through3′-5′ phosphodiester linkages. In certain embodiments theimmunostimulatory ORN of the invention are RNA. However, theimmunostimulatory ORN of the invention are not limited to RNA, as willbe described below.

An immunostimulatory ORN of the invention can in one embodiment includeone or more modified nucleobases i.e., derivatives of A, C, G, and U.Specific embodiments of these modified nucleobases include but are notlimited to 5-substituted cytosines (e.g. 5-methyl-cytosine,5-fluoro-cytosine, 5-chloro-cytosine, 5-bromo-cytosine, 5-iodo-cytosine,5-hydroxy-cytosine, 5-hydroxymethyl-cytosine, 5-difluoromethyl-cytosine,and unsubstituted or substituted 5-alkynyl-cytosine), 6-substitutedcytosines, N4-substituted cytosines (e.g. N4-ethyl-cytosine),5-aza-cytosine, 2-mercapto-cytosine, isocytosine, pseudo-isocytosine,cytosine analogs with condensed ring systems (e.g. N,N′-propylenecytosine or phenoxazine), and uracil and its derivatives (e.g.5-fluoro-uracil, 5-bromo-uracil, 5-bromovinyl-uracil, 4-thio-uracil,5-hydroxy-uracil, 5-propynyl-uracil), thymine derivatives (e.g.2-thiothymine, 4-thiothymine, 6-substituted thymines), guanosinederivatives (7-deazaguanine, 7-deaza-7-substituted guanine (such as7-deaza-7-(C2-C6)alkynylguanine), 7-deaza-8-substituted guanine,hypoxanthine, N2-substituted guanines (e.g. N2-methyl-guanine),8-substituted guanine (e.g. 8-hydroxyguanine and 8-bromoguanine), and6-thioguanine), or adenosine derivatives(5-amino-3-methyl-3H,6H-thiazolo[4,5-d]pyrimidine-2,7-dione,2,6-diaminopurine, 2-aminopurine, purine, indole, adenine, substitutedadenines (e.g. N6-methyl-adenine, 8-oxo-adenine)). The base can also besubstituted by a universal base (e.g. 4-methyl-indole, 5-nitro-indole,3-nitropyrrole, P-base, and K-base), an aromatic ring system (e.g.benzimidazole or dichloro-benzimidazole,1-methyl-1H-[1,2,4]triazole-3-carboxylic acid amide) an aromatic ringsystem (e.g. fluorobenzene or difluorobenzene) or a hydrogen atom(dSpacer). Preferred base modifications are uracil and 7-deaza-guanine.These modified U nucleobases and their corresponding ribonucleosides areavailable from commercial suppliers.

Specific embodiments of modified G nucleobases includeN²-dimethylguanine, 7-deazaguanine, 8-azaguanine, 7-deaza-7-substitutedguanine, 7-deaza-7-(C2-C6)alkynylguanine, 7-deaza-8-substituted guanine,8-hydroxyguanine, 6-thioguanine, and 8-oxoguanine. In one embodiment themodified G nucleobase is 8-hydroxyguanine. These modified G nucleobasesand their corresponding ribonucleosides are available from commercialsuppliers.

In certain embodiments at least one β-ribose unit may be replaced byβ-D-deoxyribose or a modified sugar unit, wherein the modified sugarunit is for example selected from β-D-ribose, α-D-ribose, β-L-ribose (asin ‘Spiegelmers’), α-L-ribose, 2′-amino-2′-deoxyribose,2′-fluoro-2′-deoxyribose, 2′-O—(C1-C6)alkyl-ribose, preferably2′-O—(C1-C6)alkyl-ribose is 2′-O-methylribose,2′-O—(C2-C6)alkenyl-ribose, 2′-[O—(C1-C6)alkyl-O—(C1-C6)alkyl]-ribose,LNA and α-LNA (Nielsen P et al. (2002) Chemistry-A European Journal8:712-22), β-D-xylo-furanose, α-arabinofuranose, 2′-fluoroarabinofuranose, and carbocyclic and/or open-chain sugar analogs(described, for example, in Vandendriessche et al. (1993) Tetrahedron49:7223) and/or bicyclosugar analogs (described, for example, in TarkovM et al. (1993) Helv Chim Acta 76:481).

Individual ribonucleotides and ribonucleosides of the immunostimulatoryORN of the invention may alternatively be linked by non-nucleotidiclinkers, in particular abasic linkers (dSpacers), triethylene glycolunits, or hexaethylene glycol units. Additional linkers are alkylaminolinkers, such as C3, C6, and C12 aminolinkers, and also alkylthiollinkers, such as C3 or C6 thiol linkers. Individual nucleotides andribonucleosides of the immunostimulatory ORN of the invention mayalternatively be linked by aromatic residues which may be furthersubstituted by alkyl or substituted alkyl groups.

RNA is a polymer of ribonucleotides joined through 3′-5′ phosphodiesterlinkages. Nucleotides of the immunostimulatory ORN of the invention canalso be joined through 3′-5′ phosphodiester linkages. However, theinvention also encompasses immunostimulatory ORN having unusualinternucleotide linkages, including specifically5′-5′,3′-3′,2′-2′,2′-3′, and 2′-5′ internucleotide linkages. In oneembodiment such unusual linkages are excluded from the immunostimulatoryRNA motif, even though one or more of such linkages may occur elsewherewithin the immunostimulatory ORN. For immunostimulatory ORN having freeends, inclusion of one 3′-3′ internucleotide linkage can result in animmunostimulatory ORN having two free 5′ ends. Conversely, forimmunostimulatory ORN having free ends, inclusion of one 5′-5′internucleotide linkage can result in an immunostimulatory ORN havingtwo free 3′ ends.

An immunostimulatory composition of this invention can contain two ormore immunostimulatory RNA motifs which can be linked through abranching unit. The internucleotide linkages can be3′-5′,5′-5′,3′-3′,2′-2′,2′-3′, or 2′-5′ linkages. Thereby, thenomenclature 2′-5′ is chosen according to the carbon atom of ribose. Theunusual internucleotide linkage can be a phosphodiester linkage, but itcan alternatively be modified as phosphorothioate or any other modifiedlinkage as described herein. The formula below shows a general structurefor branched immunostimulatory ORN of the invention via a nucleotidicbranching unit. Thereby Nu₁, Nu₂, and Nu₃ can be linked through3′-5′,5′-5′,3′-3′,2′-2′,2′-3′, or 2′-5′-linkages. Branching ofimmunostimulatory ORN can also involve the use of non-nucleotidiclinkers and abasic spacers. In one embodiment, Nu₁, Nu₂, and Nu₃represent identical or different immunostimulatory RNA motifs. Inanother embodiment, Nu₁, Nu₂, and Nu₃ comprises at least oneimmunostimulatory RNA motif and at least one immunostimulatory CpG DNAmotif.

The immunostimulatory ORN may contain a doubler or trebler unit (GlenResearch, Sterling, Va.), in particular those immunostimulatory ORN witha 3′-3′ linkage. A doubler unit in one embodiment can be based on1,3-bis-[5-(4,4′-dimethoxytrityloxy)pentylamido]propyl-2-[(2-cyanoethyl)-(N,N-diisopropyl)]-phosphoramidite.A trebler unit in one embodiment can be based on incorporation ofTris-2,2,2-[3-(4,4′-dimethoxytrityloxy)propyloxymethyl]ethyl-[(2-cyanoethyl)-(N,N-diisopropyl)]-phosphoramidite.Branching of the immunostimulatory ORN by multiple doubler, trebler, orother multiplier units leads to dendrimers which are a furtherembodiment of this invention. Branched immunostimulatory ORN may lead tocrosslinking of receptors for immunostimulatory RNA such as TLR3, TLR7,and TLR8, with distinct immune effects compared to non-branched forms ofthe immunostimulatory ORN. In addition, the synthesis of branched orotherwise multimeric immunostimulatory ORN may stabilize RNA againstdegradation and may enable weak or partially effective RNA sequences toexert a therapeutically useful level of immune activity. Theimmunostimulatory ORN may also contain linker units resulting frompeptide modifying reagents or oligonucleotide modifying reagents (GlenResearch). Furthermore, the immunostimulatory ORN may contain one ormore natural or unnatural amino acid residues which are connected to thepolymer by peptide (amide) linkages.

The 3′-5′,5′-5′,3′-3′,2′-2′,2′-3′, and 2′-5′ internucleotide linkagescan be direct or indirect. Direct linkages in this context refers to aphosphate or modified phosphate linkage as disclosed herein, without anintervening linker moiety. An intervening linker moiety is an organicmoiety distinct from a phosphate or modified phosphate linkage asdisclosed herein, which can include, for example, polyethylene glycol,triethylene glycol, hexaethylene glycol, dSpacer (i.e., an abasicdeoxynucleotide), doubler unit, or trebler unit.

In certain embodiments the immunostimulatory ORN is conjugated toanother entity to provide a conjugate. As used herein a conjugate refersto a combination of any two or more entities bound to one another by anyphysicochemical means, including hydrophobic interaction and covalentcoupling.

In another embodiment, the immunostimulatory ORN may be conjugated to asmall molecular weight ligand which is recognized by an immunomodulatoryreceptor. This receptor is preferably a member of the TLR family, suchas TLR2, TLR3, TLR4, TLR7, TLR8, or TLR9. The small molecular weightligands are mimics of the natural ligands for these receptors. Examplesinclude but are not limited to R-848 (Resiquimod), R-837 (Imiquimod;ALDARA™, 3M Pharmaceuticals), 7-deaza-guanosine,7-thia-8-oxo-guansosine, and 7-allyl-8-oxo-guansosine (Loxoribine) whichstimulate either TLR7 or TLR8. D-Glucopyranose derivatives, such as3D-MPL (TLR4 ligand), may also be conjugated to the immunostimulatoryORN. Pam3-Cys is an example of a TLR2 ligand which can be conjugated toimmunostimulatory ORN. Oligodeoxynucleotides containing CpG motifs areTLR9 ligands, and these can also be conjugated to immunostimulatory ORNof the invention. In one embodiment, at least one oligodeoxynucleotidecomprising a CpG motif effective for stimulating TLR9 signaling isconjugated to an immunostimulatory ORN of the invention. Conjugation ofligands for different TLRs into one molecule may lead to multimerisationof receptors which results in enhanced immune stimulation or a differentimmunostimulatory profile from that resulting from any single suchligand.

In one aspect the invention provides a conjugate of an immunostimulatoryORN of the invention and a lipophilic moiety. In certain embodiments theimmunostimulatory ORN is covalently linked to a lipophilic moiety. Thelipophilic moiety generally will occur at one or more ends of animmunostimulatory ORN having free ends, although in certain embodimentsthe lipophilic moiety can occur elsewhere along the immunostimulatoryORN and thus does not require the immunostimulatory ORN have a free end.In one embodiment the immunostimulatory ORN has a 3′ end and thelipophilic moiety is covalently linked to the 3′ end. The lipophilicgroup in general can be a cholesteryl, a modified cholesteryl, acholesterol derivative, a reduced cholesterol, a substitutedcholesterol, cholestan, C16 alkyl chain, a bile acid, cholic acid,taurocholic acid, deoxycholate, oleyl litocholic acid, oleoyl cholenicacid, a glycolipid, a phospholipid, a sphingolipid, an isoprenoid, suchas steroids, vitamins, such as vitamin E, saturated fatty acids,unsaturated fatty acids, fatty acid esters, such as triglycerides,pyrenes, porphyrines, Texaphyrine, adamantane, acridines, biotin,coumarin, fluorescein, rhodamine, Texas-Red, digoxygenin,dimethoxytrityl, t-butyldimethylsilyl, t-butyldiphenylsilyl, cyaninedyes (e.g. Cy3 or Cy5), Hoechst 33258 dye, psoralen, or ibuprofen. Incertain embodiments the lipophilic moiety is chosen from cholesteryl,palmityl, and fatty acyl. In one embodiment the lipohilic moiety ischolesteryl. It is believed that inclusion of one or more of suchlipophilic moieties in the immunostimulatory ORN of the inventionconfers upon them yet additional stability against degradation bynucleases. Where there are two or more lipophilic moieties in a singleimmunostimulatory ORN of the invention, each lipophilic moiety can beselected independently of any other.

In one embodiment the lipophilic group is attached to a 2′-position of anucleotide of the immunostimulatory ORN. A lipophilic group canalternatively or in addition be linked to the heterocyclic nucleobase ofa nucleotide of the immunostimulatory ORN. The lipophilic moiety can becovalently linked to the immunostimulatory ORN via any suitable director indirect linkage. In one embodiment the linkage is direct and is anester or an amide. In one embodiment the linkage is indirect andincludes a spacer moiety, for example one or more abasic nucleotideresidues, oligoethyleneglycol, such as triethyleneglycol (spacer 9) orhexaethylenegylcol (spacer 18), or an alkane-diol, such as butanediol.

In one embodiment the immunostimulatory ORN of the invention isadvantageously combined with a cationic lipid or a cationic peptide.Cationic lipids and cationic peptides are believed to assist intrafficking of the immunstimulatory ORN into the endosomal compartment,where TLR8 is found. In one embodiment the cationic lipid is DOTAP(N-[1-(2,3-dioleoyloxy)propy-1]-N,N,N-trimethylammonium methyl-sulfate).DOTAP is believed to transport RNA oligomer into cells and specificallytraffic to the endosomal compartment, where it can release the RNAoligomer in a pH-dependent fashion. Once in the endosomal compartment,the RNA can interact with certain intracellular TLRs, triggeringTLR-mediated signal transduction pathways involved in generating animmune response. Other agents with similar properties includingtrafficking to the endosomal compartment can be used in place of or inaddition to DOTAP. Other lipid formulations include, for example, asEFFECTENE™ (a non-liposomal lipid with a special DNA condensingenhancer) and SUPERFEC™ (a novel acting dendrimeric technology).Liposomes are commercially available from Gibco BRL, for example, asLIPOFECTIN™ and LIPOFECTACE™, which are formed of cationic lipids suchas N-[1-(2,3 dioleyloxy)-propyl]-N,N, N-trimethylammonium chloride(DOTMA) and dimethyl dioctadecylammonium bromide (DDAB). Methods formaking liposomes are well known in the art and have been described inmany publications. Liposomes also have been reviewed by Gregoriadis G(1985) Trends Biotechnol 3:235-241.

In one embodiment the immunostimulatory ORN of the invention are in theform of covalently closed, dumbbell-shaped molecules with both primaryand secondary structure. As described below, in one embodiment suchcyclic oligoribonucleotides include two single-stranded loops connectedby an intervening double-stranded segment. In one embodiment at leastone single-stranded loop includes an immunostimulatory RNA motif of theinvention. Other covalently closed, dumbbell-shaped molecules of theinvention include chimeric DNA:RNA molecules in which, for example, thedouble-stranded segment is at least partially DNA (e.g., eitherhomodimeric dsDNA or heterodimeric DNA:RNA) and at least onesingle-stranded loop includes an immunostimulatory RNA motif of theinvention. Alternatively, the double stranded segment of the chimericmolecule is RNA.

In certain embodiments the immunostimulatory ORN is isolated. Anisolated molecule is a molecule that is substantially pure and is freeof other substances with which it is ordinarily found in nature or in invivo systems to an extent practical and appropriate for its intendeduse. In particular, the immunostimulatory ORN are sufficiently pure andare sufficiently free from other biological constituents of cells so asto be useful in, for example, producing pharmaceutical preparations.Because an isolated immunostimulatory ORN of the invention may beadmixed with a pharmaceutically acceptable carrier in a pharmaceuticalpreparation, the immunostimulatory ORN may comprise only a smallpercentage by weight of the preparation. The immunostimulatory ORN isnonetheless substantially pure in that it has been substantiallyseparated from the substances with which it may be associated in livingsystems.

For use in the instant invention the immunostimulatory ORN of theinvention can be synthesized de novo using or adapted from any of anumber of procedures well known in the art. For example, theβ-cyanoethyl phosphoramidite method (Beaucage S L et al. (1981)Tetrahedron Lett 22:1859); nucleoside H-phosphonate method (Garegg P etal. (1986) Tetrahedron Lett 27:4051-4; Froehler B C et al. (1986) NuclAcid Res 14:5399-407; Garegg P et al. (1986) Tetrahedron Lett 27:4055-8;Gaffney B L et al. (1988) Tetrahedron Lett 29:2619-22). Thesechemistries can be performed by a variety of automated nucleic acidsynthesizers available in the market. Additional synthesis methodsuseful according to the instant invention are disclosed in Uhlmann E etal. (1990) Chem Rev 90:544-84, and Goodchild J (1990) Bioconjugate Chem1:165.

Oligoribonucleotide synthesis can be performed either in solution or ona solid-phase support. In solution, block coupling reactions (dimers,trimers, tetramers, etc.) are preferred, while solid-phase synthesis ispreferably performed in a stepwise process using monomeric buildingblocks. Different chemistries, such as the phosphotriester method,H-phosphonate method, and phosphoramidite method, have been described(Eckstein F (1991) Oligonucleotides and Analogues, A Practical Approach,IRL Press, Oxford). While in the phosphotriester method the reactivephosphorus group is in the oxidation state +V, the more reactivePhosphor +III derivatives are used in the coupling reactions accordingto the phosphoramidite and H-phosphonate approaches. In the latter twoapproaches, phosphorus is oxidized after the coupling step to yield thestable P(V) derivatives. If the oxidizer is iodine/water/base, thenphosphodiesters are obtained after deprotection. In contrast, if theoxidizer is a sulfurizing agent, such as Beaucage's Reagent, thenphosphorothioates are obtained after deprotection.

An efficient method for oligoribonucleotide synthesis is the combinationof solid-support synthesis using phosphoramidite chemistry as originallydescribed for oligodeoxynucleotides by Matteucci and Caruthers.Matteucci M D et al. (1981) J Am Chem Soc 103:3185.

Synthesis of oligoribonucleotides is similar to oligodeoxynucleotides,with the difference that the 2′-hydroxy group present inoligoribonucleotides must be protected by a suitable hydroxy protectinggroup. The monomers can be protected e.g. by 2′-O-t-butyldimethylsilyl(TBDMS) group in the RNA monomeric building blocks. However, RNAsynthesis using monomers containing the 2′-O-TriisopropylsilylOxyMethyl(TOM) group (TOM-Protecting-Group™) has been reported to yield highercoupling efficiency, because the TOM-Protecting-Group exhibits lowersteric hindrance than the TBDMS group. While the TBDMS protecting groupis removed using fluoride, fast deprotection is achieved for the TOMgroup using methylamine in ethanol/water at room temperature. Inoligo(ribo)nucleotide synthesis, chain elongation from 3′- to 5′-end ispreferred, which is achieved by coupling of a ribonucleotide unit havinga 3′-phosphor (III) group or its activated derivative to a free5′-hydroxy group of another nucleotide unit.

Synthesis can be conveniently performed using an automated DNA/RNAsynthesizer. Thereby, synthesis cycles as recommended by the suppliersof the synthesizers can be used. For ribonucleoside phosphoramiditemonomers, coupling times are longer (e.g., 400 sec) as compared todeoxynucleoside monomers. As solid support, 500 to 1000 Å controlledpore glass (CPG) support or organic polymer support, such as primersupport PS200 (Amersham), can be used. The solid support usuallycontains the first nucleoside, such as5′-O-Dimethoxytrityl-N-6-benzoyladenosine, attached via its 3′-end.After cleavage of the 5′-O-Dimethoxytrityl-group with trichloroaceticacid, chain elongation is achieved using e.g.5′-O-Dimethoxytrityl-N-protected-2′-O-tertbutyldimethylsilyl-nucleoside-3′-O-phosphoramidites. After successiverepetitive cycles, the completed oligoribonucleotide is cleaved from thesupport and deprotected by treatment with concentrated ammonia/ethanol(3:1, v:v) for 24 hours at 30° C. The TBDMS blocking group is finallycleaved off using triethylamine/HF. The crude oligoribonucleotides canbe purified by ion exchange high pressure liquid chromatography (HPLC),ion-pair reverse phase HPLC, or polyacrylamide gel electrophoresis(PAGE) and characterized by mass spectrometry.

Synthesis of 5′-conjugates is straightforward by coupling aphosphoramidite of the molecule to be ligated to the 5′-hydroxy group ofthe terminal nucleotide in solid-phase synthesis. A variety ofphosphoramidite derivatives of such ligands, such as cholesterol,acridine, biotin, psoralene, ethyleneglycol, or aminoalkyl residues arecommercially available. Alternatively, aminoalkyl functions can beintroduced during solid-phase synthesis which allow post-synthesisderivatization by activated conjugate molecules, such as active esters,isothiocynates, or iodo-acetamides.

Synthesis of 3′-end conjugates is usually achieved by using thecorrespondingly modified solid supports, such as e.g. commerciallyavailable cholesterol-derivatized solid supports. Conjugation canhowever also be done at internucleotide linkages, nucleobases or at theribose residues, such as at the 2′-position of ribose.

For cyclic oligoribonucleotides, the elongation of the oligonucleotidechain can be carried out on Nucleotide PS solid support (Glen Research)using standard phosphoramidite chemistry. The cyclization reaction isthen carried out on the solid support using a phosphotriester couplingprocedure (Alazzouzi et al. (1997) Nucleosides Nucleotides 16:1513-14).On final deprotection with ammonium hydroxide, virtually the onlyproduct which comes into solution is the desired cyclic oligonucleotide.

Cyclic oligoribonucleotides of the invention include closed circularforms of RNA and can include single-stranded RNA with or withoutdouble-stranded RNA. For example, in one embodiment the cyclicoligoribouncleotide includes double-stranded RNA and takes on a dumbbellconformation with two single-stranded loops connected by an interveningdouble-stranded segment. Covalently closed, dumbbell-shaped CpGoligodeoxynucleotides have been described in U.S. Pat. No. 6,849,725. Inanother embodiment the cyclic oligoribonucleotide includesdouble-stranded RNA and takes on a conformation with three or moresingle-stranded loops connected by intervening double-stranded segments.In one embodiment an immunostimulatory RNA motif is located in one ormore single-stranded segments.

The immunostimulatory ORN of the invention are useful, alone or incombination with other agents, as adjuvants. An adjuvant as used hereinrefers to a substance other than an antigen that enhances immune cellactivation in response to an antigen, e.g., a humoral and/or cellularimmune response. Adjuvants promote the accumulation and/or activation ofaccessory cells to enhance antigen-specific immune responses. Adjuvantsare used to enhance the efficacy of vaccines, i.e., antigen-containingcompositions used to induce protective immunity against the antigen.

Adjuvants in general include adjuvants that create a depot effect,immune-stimulating adjuvants, and adjuvants that create a depot effectand stimulate the immune system. An adjuvant that creates a depot effectas used herein is an adjuvant that causes the antigen to be slowlyreleased in the body, thus prolonging the exposure of immune cells tothe antigen. This class of adjuvants includes but is not limited to alum(e.g., aluminum hydroxide, aluminum phosphate); emulsion-basedformulations including mineral oil, non-mineral oil, water-in-oil oroil-in-water-in oil emulsion, oil-in-water emulsions such as Seppic ISAseries of Montanide adjuvants (e.g., Montanide ISA 720; AirLiquide,Paris, France); MF-59 (a squalene-in-water emulsion stabilized with Span85 and Tween 80; Chiron Corporation, Emeryville, Calif.); and PROVAX (anoil-in-water emulsion containing a stabilizing detergent and amicelle-forming agent; IDEC Pharmaceuticals Corporation, San Diego,Calif.).

An immune-stimulating adjuvant is an adjuvant that causes activation ofa cell of the immune system. It may, for instance, cause an immune cellto produce and secrete cytokines. This class of adjuvants includes butis not limited to saponins purified from the bark of the Q. saponariatree, such as QS21 (a glycolipid that elutes in the 21 st peak with HPLCfractionation; Aquila Biopharmaceuticals, Inc., Worcester, Mass.);poly[di(carboxylatophenoxy)phosphazene (PCPP polymer; Virus ResearchInstitute, USA); derivatives of lipopolysaccharides such asmonophosphoryl lipid A (MPL; Ribi ImmunoChem Research, Inc., Hamilton,Mont.), muramyl dipeptide (MDP; Ribi) and threonyl-muramyl dipeptide(t-MDP; Ribi); OM-174 (a glucosamine disaccharide related to lipid A; OMPharma SA, Meyrin, Switzerland); and Leishmania elongation factor (apurified Leishmania protein; Corixa Corporation, Seattle, Wash.). Thisclass of adjuvants also includes CpG DNA.

Adjuvants that create a depot effect and stimulate the immune system arethose compounds which have both of the above-identified functions. Thisclass of adjuvants includes but is not limited to ISCOMS(immunostimulating complexes which contain mixed saponins, lipids andform virus-sized particles with pores that can hold antigen; CSL,Melbourne, Australia); SB-AS2 (SmithKline Beecham adjuvant system #2which is an oil-in-water emulsion containing MPL and QS21: SmithKlineBeecham Biologicals [SBB], Rixensart, Belgium); SB-AS4 (SmithKlineBeecham adjuvant system #4 which contains alum and MPL; SBB, Belgium);non-ionic block copolymers that form micelles such as CRL 1005 (thesecontain a linear chain of hydrophobic polyoxypropylene flanked by chainsof polyoxyethylene; Vaxcel, Inc., Norcross, Ga.); and Syntex AdjuvantFormulation (SAF, an oil-in-water emulsion containing Tween 80 and anonionic block copolymer; Syntex Chemicals, Inc., Boulder, Colo.).

The invention in one aspect provides an adjuvant that includes animmunostimulatory ORN of the invention, by itself. In another embodimentthe invention provides an adjuvant that includes an immunostimulatoryORN of the invention and at least one other adjuvant (a combinationadjuvant). The other adjuvant can include an adjuvant that creates adepot effect, an immune-stimulating adjuvant, an adjuvant that creates adepot effect and stimulates the immune system, and any combinationthereof. In one embodiment the immunostimulatory ORN of the inventionand at least one other adjuvant are covalently linked to one another. Acombination adjuvant according to the invention may exhibit asynergistic immunostimulatory effect compared to the sum of effects ofthe immunostimulatory ORN alone and the at least one other adjuvantalone. Additionally or alternatively, a combination adjuvant accordingto the invention may exhibit an altered immunostimulatory profilecompared to that of either the immunostimulatory ORN alone or the atleast one other adjuvant alone. For example, the combination adjuvantmay provide a more balanced form of Th1/Th2 immunostimulation in oneembodiment, or it may provide a more skewed form of Th1/Th2immunostimulation in another embodiment. Those skilled in the art willrecognize how to select individual components to promote a desired typeof immunostimulation, e.g., more balanced or more skewed with respect toTh1 and Th2 character. Th1 and Th2 are described further below.

Also provided is a composition that includes an immunostimulatory ORN ofthe invention plus another adjuvant, wherein the other adjuvant is acytokine. In one embodiment the composition is a conjugate of theimmunostimulatory ORN of the invention and the cytokine.

Cytokines are soluble proteins and glycoproteins produced by many typesof cells that mediate inflammatory and immune reactions. Cytokinesmediate communication between cells of the immune system, acting locallyas well as systemically to recruit cells and to regulate their functionand proliferation. Categories of cytokines include mediators andregulators of innate immunity, mediators and regulators of adaptiveimmunity, and stimulators of hematopoiesis. Included among cytokines areinterleukins (e.g., IL-1, IL-2, IL-3, IL-4, IL-5, IL-6, IL-7, IL-8,IL-9, IL-10, IL-11, IL-12, IL-13, IL-14, IL-15, IL-16, IL-17, IL-18, andinterleukins 19-32 (IL-19-IL-32), among others), chemokines (e.g.,IP-10, RANTES, MIP-1α, MIP-1β, MIP-3α, MCP-1, MCP-2, MCP-3, MCP-4,eotaxin, I-TAC, and BCA-1, among others), as well as other cytokinesincluding type 1 interferons (e.g., IFN-α and IFN-β), type 2 interferon(e.g., IFN-γ), tumor necrosis factor-alpha (TNF-α), transforming growthfactor-beta (TGF-β), and various colony stimulating factors (CSFs),including GM-CSF, G-CSF, and M-CSF.

Also provided is a composition that includes an immunostimulatory ORN ofthe invention plus an immunostimulatory CpG nucleic acid. In oneembodiment the composition is a conjugate of the immunostimulatory ORNof the invention and the CpG nucleic acid, e.g. a RNA:DNA conjugate. Inone embodiment the composition is a mixture of the immunostimulatory ORNof the invention and the CpG nucleic acid, i.e., not a RNA:DNAconjugate.

An immunostimulatory CpG nucleic acid as used herein refers to a naturalor synthetic DNA sequence that includes a CpG motif and that stimulatesactivation or proliferation of cells of the immune system.Immunostimulatory CpG nucleic acids have been described in a number ofissued patents, published patent applications, and other publications,including U.S. Pat. Nos. 6,194,388; 6,207,646; 6,214,806; 6,218,371;6,239,116; and 6,339,068. In one embodiment the immunostimulatory CpGnucleic acid is a CpG oligodeoxynucleotide (CpG ODN) 6-100 nucleotideslong. In one embodiment the immunostimulatory CpG nucleic acid is a CpGoligodeoxynucleotide (CpG ODN) 8-40 nucleotides long.

Immunostimulatory CpG nucleic acids include different classes of CpGnucleic acids. One class is potent for activating B cells but isrelatively weak in inducing IFN-α and NK cell activation; this class hasbeen termed the B class. The B class CpG nucleic acids typically arefully stabilized and include an unmethylated CpG dinucleotide withincertain preferred base contexts. See, e.g., U.S. Pat. Nos. 6,194,388;6,207,646; 6,214,806; 6,218,371; 6,239,116; and 6,339,068. Another classis potent for inducing IFN-α and NK cell activation but is relativelyweak at stimulating B cells; this class has been termed the A class. TheA class CpG nucleic acids typically have a palindromic phosphodiesterCpG dinucleotide-containing sequence of at least 6 nucleotides and astabilized poly-G sequences at either or both the 5′ and 3′ ends. See,for example, published international patent application WO 01/22990. Yetanother class of CpG nucleic acids activates B cells and NK cells andinduces IFN-α; this class has been termed the C class. The C class CpGnucleic acids, as first characterized, typically are fully stabilized,include a B class-type sequence and a GC-rich palindrome ornear-palindrome. This class has been described in published U.S. patentapplication 2003/0148976, the entire contents of which are incorporatedherein by reference.

Immunostimulatory CpG nucleic acids also include so-called soft andsemi-soft CpG nucleic acids, as disclosed in published U.S. patentapplication 2003/0148976, the entire contents of which is incorporatedherein by reference. Such soft and semi-soft immunostimulatory CpGnucleic acids incorporate a combination of nuclease-resistant andnuclease-sensitive internucleotide linkages, wherein the different typesof linkages are positioned according to certain rules.

Also provided is a composition that includes an immunostimulatory ORN ofthe invention plus another adjuvant, wherein the other adjuvant is alipopeptide such as Pam3Cys, a cationic polysaccharide such as chitosan,or a cationic peptide such as protamine. In one embodiment thecomposition is a conjugate of the immunostimulatory ORN of the inventionand the other adjuvant.

The invention in one aspect provides a vaccine that includes animmunostimulatory ORN of the invention and an antigen. An “antigen” asused herein refers to any molecule capable of being recognized by aT-cell antigen receptor or B-cell antigen receptor. The term broadlyincludes any type of molecule which is recognized by a host immunesystem as being foreign. Antigens generally include but are not limitedto cells, cell extracts, proteins, polypeptides, peptides,polysaccharides, polysaccharide conjugates, peptide and non-peptidemimics of polysaccharides and other molecules, small molecules, lipids,glycolipids, polysaccharides, carbohydrates, viruses and viral extracts,and multicellular organisms such as parasites, and allergens. Withrespect to antigens that are proteins, polypeptides, or peptides, suchantigens can include nucleic acid molecules encoding such antigens.Antigens more specifically include, but are not limited to, cancerantigens, which include cancer cells and molecules expressed in or oncancer cells; microbial antigens, which include microbes and moleculesexpressed in or on microbes; and allergens. Accordingly, the inventionin certain embodiments provides vaccines for cancers, infectious agents,and allergens.

The invention in one aspect provides a use of an immunostimulatory ORNof the invention for the preparation of a medicament for vaccinating asubject.

The invention in one aspect provides a method for preparing a vaccine.The method includes the step of placing an immunostimulatory ORN of theinvention in intimate association with an antigen and, optionally, apharmaceutically acceptable carrier.

In various embodiments the antigen is a microbial antigen, a cancerantigen, or an allergen. A “microbial antigen” as used herein is anantigen of a microorganism and includes but is not limited to viruses,bacteria, parasites, and fungi. Such antigens include the intactmicroorganism as well as natural isolates and fragments or derivativesthereof and also synthetic compounds which are identical to or similarto natural microorganism antigens and induce an immune response specificfor that microorganism. A compound is similar to a natural microorganismantigen if it induces an immune response (humoral and/or cellular) to anatural microorganism antigen. Such antigens are used routinely in theart and are well known to those of ordinary skill in the art.

Viruses are small infectious agents which generally contain a nucleicacid core and a protein coat, but are not independently livingorganisms. Viruses can also take the form of infectious nucleic acidslacking a protein. A virus cannot survive in the absence of a livingcell within which it can replicate. Viruses enter specific living cellseither by endocytosis or direct injection of DNA (phage) and multiply,causing disease. The multiplied virus can then be released and infectadditional cells. Some viruses are DNA-containing viruses and others areRNA-containing viruses. In some aspects, the invention also intends totreat diseases in which prions are implicated in disease progressionsuch as for example bovine spongiform encephalopathy (i.e., mad cowdisease, BSE) or scrapie infection in animals, or Creutzfeldt-Jakobdisease in humans.

Viruses include, but are not limited to, enteroviruses (including, butnot limited to, viruses that the family picornaviridae, such as poliovirus, coxsackie virus, echo virus), rotaviruses, adenovirus, hepatitisvirus. Specific examples of viruses that have been found in humansinclude but are not limited to: Retroviridae (e.g., humanimmunodeficiency viruses, such as HIV-1 (also referred to as HTLV-III,LAV or HTLV-III/LAV, or HIV-III; and other isolates, such as HIV-LP;Picornaviridae (e.g., polio viruses, hepatitis A virus; enteroviruses,human Coxsackie viruses, rhinoviruses, echoviruses); Calciviridae (e.g.,strains that cause gastroenteritis); Togaviridae (e.g., equineencephalitis viruses, rubella viruses); Flaviviridae (e.g., dengueviruses, encephalitis viruses, yellow fever viruses); Coronaviridae(e.g., coronaviruses); Rhabdoviridae (e.g., vesicular stomatitisviruses, rabies viruses); Filoviridae (e.g., ebola viruses);Paramyxoviridae (e.g., parainfluenza viruses, mumps virus, measlesvirus, respiratory syncytial virus); Orthomyxoviridae (e.g., influenzaviruses); Bunyaviridae (e.g., Hantaan viruses, bunya viruses,phleboviruses and Nairo viruses); Arenaviridae (hemorrhagic feverviruses); Reoviridae (e.g., reoviruses, orbiviurses and rotaviruses);Birnaviridae; Hepadnaviridae (Hepatitis B virus); Parvoviridae(parvoviruses); Papovaviridae (papillomaviruses, polyoma viruses);Adenoviridae (most adenoviruses); Herpesviridae (herpes simplex virus(HSV) 1 and 2, varicella zoster virus, cytomegalovirus (CMV));Poxyiridae (variola viruses, vaccinia viruses, pox viruses);Iridoviridae (e.g., African swine fever virus); and unclassified viruses(e.g., the etiological agents of spongiform encephalopathies, the agentof delta hepatitis (thought to be a defective satellite of hepatitis Bvirus), the agents of non-A, non-B hepatitis (class 1=internallytransmitted; class 2=parenterally transmitted (i.e., Hepatitis C);Norwalk and related viruses, and astroviruses).

Bacteria are unicellular organisms which multiply asexually by binaryfission. They are classified and named based on their morphology,staining reactions, nutrition and metabolic requirements, antigenicstructure, chemical composition, and genetic homology. Bacteria can beclassified into three groups based on their morphological forms,spherical (coccus), straight-rod (bacillus) and curved or spiral rod(vibrio, campylobacter, spirillum, and spirochaete). Bacteria are alsomore commonly characterized based on their staining reactions into twoclasses of organisms, gram-positive and gram-negative. Gram refers tothe method of staining which is commonly performed in microbiology labs.Gram-positive organisms retain the stain following the stainingprocedure and appear a deep violet color. Gram-negative organisms do notretain the stain but take up the counter-stain and thus appear pink.

Infectious bacteria include, but are not limited to, gram negative andgram positive bacteria. Gram positive bacteria include, but are notlimited to Pasteurella species, Staphylococci species, and Streptococcusspecies. Gram negative bacteria include, but are not limited to,Escherichia coli, Pseudomonas species, and Salmonella species. Specificexamples of infectious bacteria include but are not limited to:Helicobacter pyloris, Borrelia burgdorferi, Legionella pneumophilia,Mycobacteria sps (e.g., M. tuberculosis, M. avium, M. intracellulare, M.kansasii, M. gordonae), Staphylococcus aureus, Neisseria gonorrhoeae,Neisseria meningitidis, Listeria monocytogenes, Streptococcus pyogenes(Group A Streptococcus), Streptococcus agalactiae (Group BStreptococcus), Streptococcus (viridans group), Streptococcus faecalis,Streptococcus bovis, Streptococcus (anaerobic species), Streptococcuspneumoniae, pathogenic Campylobacter sp., Enterococcus sp., Haemophilusinfluenzae, Bacillus anthracis, Corynebacterium diphtheriae,Corynebacterium sp., Erysipelothrix rhusiopathiae, Clostridiumperfringens, Clostridium tetani, Enterobacter aerogenes, Klebsiellapneumoniae, Pasturella multocida, Bacteroides sp., Fusobacteriumnucleatum, Streptobacillus moniliformis, Treponema pallidum, Treponemapertenue, Leptospira, Rickettsia, and Actinomyces israelli.

Parasites are organisms which depend upon other organisms in order tosurvive and thus must enter, or infect, another organism to continuetheir life cycle. The infected organism, i.e., the host, provides bothnutrition and habitat to the parasite. Although in its broadest sensethe term parasite can include all infectious agents (i.e., bacteria,viruses, fungi, protozoa and helminths), generally speaking, the term isused to refer solely to protozoa, helminths, and ectoparasiticarthropods (e.g., ticks, mites, etc.). Protozoa are single-celledorganisms which can replicate both intracellularly and extracellularly,particularly in the blood, intestinal tract or the extracellular matrixof tissues. Helminths are multicellular organisms which almost alwaysare extracellular (an exception being Trichinella spp.). Helminthsnormally require exit from a primary host and transmission into asecondary host in order to replicate. In contrast to theseaforementioned classes, ectoparasitic arthropods form a parasiticrelationship with the external surface of the host body.

Parasites include intracellular parasites and obligate intracellularparasites. Examples of parasites include but are not limited toPlasmodium falciparum, Plasmodium ovale, Plasmodium malariae,Plasmdodium vivax, Plasmodium knowlesi, Babesia microti, Babesiadivergens, Trypanosoma cruzi, Toxoplasma gondii, Trichinella spiralis,Leishmania major, Leishmania donovani, Leishmania braziliensis,Leishmania tropica, Trypanosoma gambiense, Trypanosoma rhodesiense andSchistosoma mansoni.

Fungi are eukaryotic organisms, only a few of which cause infection invertebrate mammals. Because fungi are eukaryotic organisms, they differsignificantly from prokaryotic bacteria in size, structuralorganization, life cycle and mechanism of multiplication. Fungi areclassified generally based on morphological features, modes ofreproduction and culture characteristics. Although fungi can causedifferent types of disease in subjects, such as respiratory allergiesfollowing inhalation of fungal antigens, fungal intoxication due toingestion of toxic substances, such as Amanita phalloides toxin andphallotoxin produced by poisonous mushrooms and aflatoxins, produced byaspergillus species, not all fungi cause infectious disease.

Infectious fungi can cause systemic or superficial infections. Primarysystemic infection can occur in normal healthy subjects, andopportunistic infections are most frequently found in immunocompromisedsubjects. The most common fungal agents causing primary systemicinfection include Blastomyces, Coccidioides, and Histoplasma. Commonfungi causing opportunistic infection in immunocompromised orimmunosuppressed subjects include, but are not limited to, Candidaalbicans, Cryptococcus neoformans, and various Aspergillus species.Systemic fungal infections are invasive infections of the internalorgans. The organism usually enters the body through the lungs,gastrointestinal tract, or intravenous catheters. These types ofinfections can be caused by primary pathogenic fungi or opportunisticfungi.

Superficial fungal infections involve growth of fungi on an externalsurface without invasion of internal tissues. Typical superficial fungalinfections include cutaneous fungal infections involving skin, hair, ornails.

Diseases associated with fungal infection include aspergillosis,blastomycosis, candidiasis, chromoblastomycosis, coccidioidomycosis,cryptococcosis, fungal eye infections, fungal hair, nail, and skininfections, histoplasmosis, lobomycosis, mycetoma, otomycosis,paracoccidioidomycosis, disseminated Penicillium marneffei,phaeohyphomycosis, rhinosporidioisis, sporotrichosis, and zygomycosis.

Other medically relevant microorganisms have been described extensivelyin the literature, e.g., see C. G. A Thomas, Medical Microbiology,Bailliere Tindall, Great Britain 1983, the entire contents of which ishereby incorporated by reference. Each of the foregoing lists isillustrative and is not intended to be limiting.

As used herein, the terms “cancer antigen” and “tumor antigen” are usedinterchangeably to refer to a compound, such as a peptide, protein, orglycoprotein, which is associated with a tumor or cancer cell and whichis capable of provoking an immune response when expressed on the surfaceof an antigen-presenting cell in the context of a majorhistocompatibility complex (MHC) molecule. Cancer antigens which aredifferentially expressed by cancer cells and can thereby be exploited inorder to target cancer cells. Cancer antigens are antigens which canpotentially stimulate apparently tumor-specific immune responses. Someof these antigens are encoded, although not necessarily expressed, bynormal cells. These antigens can be characterized as those which arenormally silent (i.e., not expressed) in normal cells, those that areexpressed only at certain stages of differentiation, and those that aretemporally expressed such as embryonic and fetal antigens. Other cancerantigens are encoded by mutant cellular genes, such as oncogenes (e.g.,activated ras oncogene), suppressor genes (e.g., mutant p53), fusionproteins resulting from internal deletions or chromosomaltranslocations. Still other cancer antigens can be encoded by viralgenes such as those carried on RNA and DNA tumor viruses.

Cancer antigens can be prepared from cancer cells either by preparingcrude extracts of cancer cells, for example, as described in Cohen P Aet al. (1994) Cancer Res 54:1055-8, by partially purifying the antigens,by recombinant technology, or by de novo synthesis of known antigens.Cancer antigens include but are not limited to antigens that arerecombinantly expressed, an immunogenic portion of, or a whole tumor orcancer or cell thereof. Such antigens can be isolated or preparedrecombinantly or by any other means known in the art.

Examples of tumor antigens include MAGE, MART-1/Melan-A, gp100,dipeptidyl peptidase IV (DPPIV), adenosine deaminase-binding protein(ADAbp), cyclophilin b, colorectal associated antigen(CRC)-C017-1A/GA733, carcinoembryonic antigen (CEA) and its immunogenicepitopes CAP-1 and CAP-2, etv6, aml1, prostate specific antigen (PSA)and its immunogenic epitopes PSA-1, PSA-2, and PSA-3, prostate-specificmembrane antigen (PSMA), T-cell receptor/CD3-zeta chain, MAGE-family oftumor antigens (e.g., MAGE-A1, MAGE-A2, MAGE-A3, MAGE-A4, MAGE-A5,MAGE-A6, MAGE-A7, MAGE-A8, MAGE-A9, MAGE-A10, MAGE-A11, MAGE-A12,MAGE-Xp2 (MAGE-B2), MAGE-Xp3 (MAGE-B3), MAGE-Xp4 (MAGE-B4), MAGE-C1,MAGE-C2, MAGE-C3, MAGE-C4, MAGE-C5), GAGE-family of tumor antigens(e.g., GAGE-1, GAGE-2, GAGE-3, GAGE-4, GAGE-5, GAGE-6, GAGE-7, GAGE-8,GAGE-9), BAGE, RAGE, LAGE-1, NAG, GnT-V, MUM-1, CDK4, tyrosinase, p53,MUC family, HER2/neu, p21ras, RCAS1, α-fetoprotein, E-cadherin,α-catenin, β-catenin and γ-catenin, p120ctn, gp100^(Pmel117), PRAME,NY-ESO-1, cdc27, adenomatous polyposis coli protein (APC), fodrin,Connexin 37, Ig-idiotype, p15, gp75, GM2 and GD2 gangliosides, viralproducts such as human papillomavirus proteins, Smad family of tumorantigens, lmp-1, P1A, EBV-encoded nuclear antigen (EBNA)-1, brainglycogen phosphorylase, SSX-1, SSX-2 (HOM-MEL-40), SSX-1, SSX-4, SSX-5,SCP-1 and CT-7, and c-erbB-2. This list is not meant to be limiting.

An “allergen” as used herein is a molecule capable of provoking animmune response characterized by production of IgE. An allergen is alsoa substance that can induce an allergic or asthmatic response in asusceptible subject. Thus, in the context of this invention, the termallergen means a specific type of antigen which can trigger an allergicresponse which is mediated by IgE antibody.

The list of allergens is enormous and can include pollens, insectvenoms, animal dander dust, fungal spores and drugs (e.g., penicillin).Examples of natural animal and plant allergens include proteins specificto the following genuses: Canis (Canis familiaris); Dermatophagoides(e.g., Dermatophagoides farinae); Felis (Felis domesticus); Ambrosia(Ambrosia artemisiifolia); Lolium (e.g., Lolium perenne and Loliummultiflorum); Cryptomeria (Cryptomeria japonica); Alternaria (Alternariaalternata); Alder; Alnus (Alnus gultinosa); Betula (Betula verrucosa);Quercus (Quercus alba); Olea (Olea europa); Artemisia (Artemisiavulgaris); Plantago (e.g., Plantago lanceolata); Parietaria (e.g.,Parietaria officinalis and Parietaria judaica); Blattella (e.g.,Blattella germanica); Apis (e.g., Apis multiflorum); Cupressus (e.g.,Cupressus sempervirens, Cupressus arizonica and Cupressus macrocarpa);Juniperus (e.g., Juniperus sabinoides, Juniperus virginiana, Juniperuscommunis, and Juniperus ashei); Thuya (e.g., Thuya orientalis);Chamaecyparis (e.g., Chamaecyparis obtusa); Periplaneta (e.g.,Periplaneta americana); Agropyron (e.g., Agropyron repens); Secale(e.g., Secale cereale); Triticum (e.g., Triticum aestivum); Dactylis(e.g., Dactylis glomerata); Festuca (e.g., Festuca elatior); Poa (e.g.,Poa pratensis and Poa compressa); Avena (e.g., Avena sativa); Holcus(e.g., Holcus lanatus); Anthoxanthum (e.g., Anthoxanthum odoratum);Arrhenatherum (e.g., Arrhenatherum elatius); Agrostis (e.g., Agrostisalba); Phleum (e.g., Phleum pratense); Phalaris (e.g., Phalarisarundinacea); Paspalum (e.g., Paspalum notatum); Sorghum (e.g., Sorghumhalepensis); and Bromus (e.g., Bromus inermis).

The invention in one aspect provides a conjugate of an immunostimulatoryORN of the invention and an antigen. In one embodiment theimmunostimulatory ORN of the invention is covalently linked to theantigen. The covalent linkage between the immunostimulatory ORN and theantigen can be any suitable type of covalent linkage, provided theimmunostimulatory ORN and the antigen when so joined retain measurablefunctional activity of each individual component. In one embodiment thecovalent linkage is direct. In another embodiment the covalent linkageis indirect, e.g., through a linker moiety. The covalently linkedimmunostimulatory ORN and antigen may be processed within a cell torelease one from the other. In this way delivery to a cell of eithercomponent may be enhanced compared to its delivery if administered as aseparate preparatation or separate component. In one embodiment theantigen is an antigen per se, i.e., it is a preformed antigen.

In one aspect the invention provides a pharmaceutical composition whichincludes a composition of the invention, in association with a deliveryvehicle. In various embodiments the delivery vehicle can be chosen froma cationic lipid, a liposome, a cochleate, a virosome, animmune-stimulating complex (ISCOM), a microparticle, a microsphere, ananosphere, a unilamellar vesicle (LUV), a multilamellar vesicle, anoil-in-water emulsion, a water-in-oil emulsion, an emulsome, and apolycationic peptide, and, optionally, a pharmaceutically acceptablecarrier. Pharmaceutically acceptable carriers are discussed below. Thepharmaceutical composition of the invention optionally can furtherinclude an antigen. The composition of the invention, along with theantigen when present, is brought into physical association with thedelivery vehicle using any suitable method. The immunostimulatorycomposition can be contained within the delivery vehicle, or it can bepresent on or in association with a solvent-exposed surface of thedelivery vehicle. In one embodiment the immunostimulatory ORN is presenton or in association with a solvent-exposed surface of the deliveryvehicle, and the antigen, if present, is contained within the deliveryvehicle. In another embodiment both the immunostimulatory ORN and theantigen are present on or in association with a solvent-exposed surfaceof the delivery vehicle. In yet another embodiment the antigen ispresent on or in association with a solvent-exposed surface of thedelivery vehicle, and the immunostimulatory ORN is contained within thedelivery vehicle. In yet another embodiment both the immunostimulatoryORN and the antigen, if antigen is included, are contained within thedelivery vehicle.

The invention also provides methods for use of the immunostimulatorycompositions of the invention. In one aspect the invention provides amethod of activating an immune cell. The method according to this aspectof the invention includes the step of contacting an immune cell, invitro or in vivo, with an effective amount of a composition of theinvention, to activate the immune cell. The composition of the inventioncan optionally include an antigen. An “immune cell” as used hereinrefers to any bone marrow-derived cell that can participate in an innateor adaptive immune response. Cells of the immune system include, withoutlimitation, dendritic cells (DC), natural killer (NK) cells, monocytes,macrophages, granulocytes, B lymphocytes, plasma cells, T lymphocytes,and precursor cells thereof.

As used herein, the term “effective amount” refers to that amount of asubstance that is necessary or sufficient to bring about a desiredbiological effect. An effective amount can but need not be limited to anamount administered in a single administration.

As used herein, the term “activate an immune cell” refers to inducing animmune cell to enter an activated state that is associated with animmune response. The term “activate an immune cell” refers both toinducing and augmenting an immune response. As used herein, the term“immune response” refers to any aspect of an innate or adaptive immuneresponse that reflects activation of an immune cell to proliferate, toperform an effector immune function, or to produce a gene productinvolved in an immune response. Gene products involved in an immuneresponse can include secreted products (e.g., antibodies, cytokines, andchemokines) as well as intracellular and cell surface moleculescharacteristic of immune function (e.g., certain cluster ofdifferentiation (CD) antigens, transcription factors, and genetranscripts). The term “immune response” can be applied to a single cellor to a population of cells.

Production of cytokines can be assessed by any of several methods wellknown in the art, including biological response assays, enzyme-linkedimmunosorbent assay (ELISA), intracellular fluorescence-activated cellsorting (FACS) analysis, and reverse transcriptase/polymerase chainreaction (RT-PCR).

In one embodiment the immune response involves production of apro-inflammatory cytokine immune response. A pro-inflammatory cytokineimmune response can include expression of any of certain cytokines andchemokines, including IFN-γ, TNF-α, IL-12, IL-10, IL-6, and anycombination thereof. It specifically excludes IFN-α for purposes of theinvention.

In one embodiment the immune response involves upregulation of cellsurface markers of immune cell activation, such as CD25, CD80, CD86, andCD154. Methods for measuring cell surface expression of such markers arewell known in the art and include FACS analysis.

For measurement of immune response in a cell or population of cells, inone embodiment the cell or population of cells expresses TLR8. The cellcan express the TLR naturally, or it can be manipulated to express theTLR though introduction into the cell of a suitable expression vectorfor the TLR. In one embodiment the cell or population of cells isobtained as peripheral blood mononuclear cells (PBMC). In one embodimentthe cell or population of cells is obtained as a cell line expressingthe TLR. In one embodiment the cell or population of cells is obtainedas a transient transfectant expressing the TLR. In one embodiment thecell or population of cells is obtained as a stable transfectantexpressing the TLR.

Also for use in measuring an immune response in a cell or population ofcells, it may be convenient to introduce into the cell or population ofcells a reporter construct that is responsive to intracellular signalingby a TLR. In one embodiment such a reporter is a gene placed under thecontrol of an NF-κB promoter. In one embodiment the gene placed undercontrol of the promoter is luciferase. Under suitable conditions ofactivation, the luciferase reporter construct is expressed and emits adetectable light signal that may be measured quantitatively using aluminometer. Such reporter constructs and other suitable reporterconstructs are commercially available.

The invention also contemplates the use of cell-free methods ofdetecting TLR activation.

The invention in certain aspects relates to compositions and methods foruse in therapy. The immunostimulatory compositions of the invention canbe used alone or combined with other therapeutic agents. Theimmunostimulatory composition and other therapeutic agent may beadministered simultaneously or sequentially. When the immunostimulatorycomposition of the invention and the other therapeutic agent areadministered simultaneously, they can be administered in the same orseparate formulations, but they are administered at the same time. Inaddition, when the immunostimulatory composition of the invention andthe other therapeutic agent are administered simultaneously, they can beadministered via the same or separate routes of administration, but theyare administered at the same time. The immunostimulatory composition ofthe invention and another therapeutic agent are administeredsequentially when administration of the immunostimulatory composition ofthe invention is temporally separated from administration of the othertherapeutic agent. The separation in time between the administration ofthese compounds may be a matter of minutes or it may be longer. In oneembodiment the immunostimulatory composition of the invention isadministered before administration of the other therapeutic agent. Inone embodiment the immunostimulatory composition of the invention isadministered after administration of the other therapeutic agent. Inaddition, when the immunostimulatory composition of the invention andthe other therapeutic agent are administered sequentially, they can beadministered via the same or separate routes of administration. Othertherapeutic agents include but are not limited to adjuvants, antigens,vaccines, and medicaments useful for the treatment of infection, cancer,allergy, and asthma.

In one aspect the invention provides a method of vaccinating a subject.The method according to this aspect of the invention includes the stepof administering to the subject an antigen and a composition of theinvention. In one embodiment the administering the antigen includesadministering a nucleic acid encoding the antigen.

A “subject” as used herein refers to a vertebrate animal. In variousembodiments the subject is a human, a non-human primate, or othermammal. In certain embodiments the subject is a mouse, rat, guinea pig,rabbit, cat, dog, pig, sheep, goat, cow, or horse.

For use in the method of vaccinating a subject, the composition of theinvention in one embodiment includes an antigen. The antigen can beseparate from or covalently linked to a ORN of the invention. In oneembodiment the composition of the invention does not itself include theantigen. In this embodiment the antigen can be administered to thesubject either separately from the composition of the invention, ortogether with the composition of the invention. Administration that isseparate includes separate in time, separate in location or route ofadministration, or separate both in time and in location or route ofadministration. When the composition of the invention and the antigenare administered separate in time, the antigen can be administeredbefore or after the composition of the invention. In one embodiment theantigen is administered 48 hours to 4 weeks after administration of thecomposition of the invention. The method also contemplates theadministration of one or more booster doses of antigen alone,composition alone, or antigen and composition, following an initialadministration of antigen and composition.

It is also contemplated by the invention that a subject can be preparedfor a future encounter with an unknown antigen by administering to thesubject a composition of the invention, wherein the composition does notinclude an antigen. According to this embodiment the immune system ofthe subject is prepared to mount a more vigorous response to an antigenthat is later encountered by the subject, for example throughenvironmental or occupational exposure. Such method can be used, forexample, for travellers, medical workers, and soldiers likely to beexposed to microbial agents.

In one aspect the invention provides a method of treating a subjecthaving an immune system deficiency. The method according to this aspectof the invention includes the step of administering to the subject aneffective amount of a composition of the invention to treat the subject.An “immune system deficiency” as used herein refers to an abnormallydepressed ability of an immune system to mount an immune response to anantigen. In one embodiment an immune system deficiency is a disease ordisorder in which the subject's immune system is not functioning innormal capacity or in which it would be useful to boost the subject'simmune response, for example to eliminate a tumor or cancer or aninfection in the subject. A “subject having an immune deficiency” asused herein refers to a subject in which there is a depressed ability ofthe subject's immune system to mount an immune response to an antigen.Subjects having an immune deficiency include subjects having an acquiredimmune deficiency as well as subjects having a congenital immune systemdeficiency. Subjects having acquired immune deficiency include, withoutlimitation, subjects having a chronic inflammatory condition, subjectshaving chronic renal insufficiency or renal failure, subjects havinginfection, subjects having cancer, subjects receiving immunosuppressivedrugs, subjects receiving other immunosuppressive treatment, andsubjects with malnutrition. In one embodiment the subject has asuppressed CD4+ T-cell population. In one embodiment the subject has aninfection with human immunodeficiency virus (HIV) or has acquiredimmunodeficiency syndrome (AIDS). The method according to this aspect ofthe invention thus provides a method for boosting an immune response orboosting the ability to mount an immune response in a subject in need ofa more vigorous immune response.

The compositions and methods of the invention can be used alone or inconjunction with other agents and methods useful for the treatment ofinfection. In one aspect the invention provides a method of treating asubject having an infection. The method according to this aspect of theinvention includes the step of administering to a subject having aninfection an effective amount of the composition of the invention totreat the subject.

In one aspect the invention provides a method of treating a subjecthaving an infection. The method according to this aspect of theinvention includes the step of administering to a subject having aninfection an effective amount of the composition of the invention and aninfection medicament to treat the subject.

In one aspect the invention provides a use of an immunostimulatory ORNof the invention for the preparation of a medicament for treating aninfection in a subject.

In one aspect the invention provides a composition useful for thetreatment of infection. The composition according to this aspectincludes an immunostimulatory ORN of the invention and an infectionmedicament.

As used herein, the term “treat” as used in reference to a subjecthaving a disease or condition shall mean to prevent, ameliorate, oreliminate at least one sign or symptom of the disease or condition inthe subject.

A “subject having an infection” is a subject that has a disorder arisingfrom the invasion of the subject, superficially, locally, orsystemically, by an infectious microorganism. The infectiousmicroorganism can be a virus, bacterium, fungus, or parasite, asdescribed above.

Infection medicaments include but are not limited to anti-bacterialagents, anti-viral agents, anti-fungal agents and anti-parasitic agents.Phrases such as “anti-infective agent”, “antibiotic”, “anti-bacterialagent”, “anti-viral agent”, “anti-fungal agent”, “anti-parasitic agent”and “parasiticide” have well-established meanings to those of ordinaryskill in the art and are defined in standard medical texts. Briefly,anti-bacterial agents kill or inhibit bacteria, and include antibioticsas well as other synthetic or natural compounds having similarfunctions. Anti-viral agents can be isolated from natural sources orsynthesized and are useful for killing or inhibiting viruses.Anti-fungal agents are used to treat superficial fungal infections aswell as opportunistic and primary systemic fungal infections.Anti-parasite agents kill or inhibit parasites. Many antibiotics are lowmolecular weight molecules which are produced as secondary metabolitesby cells, such as microorganisms. In general, antibiotics interfere withone or more functions or structures which are specific for themicroorganism and which are not present in host cells.

One of the problems with anti-infective therapies is the side effectsoccurring in the host that is treated with the anti-infective agent. Forinstance, many anti-infectious agents can kill or inhibit a broadspectrum of microorganisms and are not specific for a particular type ofspecies. Treatment with these types of anti-infectious agents results inthe killing of the normal microbial flora living in the host, as well asthe infectious microorganism. The loss of the microbial flora can leadto disease complications and predispose the host to infection by otherpathogens, since the microbial flora compete with and function asbarriers to infectious pathogens. Other side effects may arise as aresult of specific or non-specific effects of these chemical entities onnon-microbial cells or tissues of the host.

Another problem with widespread use of anti-infectants is thedevelopment of antibiotic-resistant strains of microorganisms. Already,vancomycin-resistant enterococci, penicillin-resistant pneumococci,multi-resistant S. aureus, and multi-resistant tuberculosis strains havedeveloped and are becoming major clinical problems. Widespread use ofanti-infectants will likely produce many antibiotic-resistant strains ofbacteria. As a result, new anti-infective strategies will be required tocombat these microorganisms.

Antibacterial antibiotics which are effective for killing or inhibitinga wide range of bacteria are referred to as broad-spectrum antibiotics.Other types of antibacterial antibiotics are predominantly effectiveagainst the bacteria of the class gram-positive or gram-negative. Thesetypes of antibiotics are referred to as narrow-spectrum antibiotics.Other antibiotics which are effective against a single organism ordisease and not against other types of bacteria, are referred to aslimited-spectrum antibiotics.

Anti-bacterial agents are sometimes classified based on their primarymode of action. In general, anti-bacterial agents are cell wallsynthesis inhibitors, cell membrane inhibitors, protein synthesisinhibitors, nucleic acid synthesis or functional inhibitors, andcompetitive inhibitors. Cell wall synthesis inhibitors inhibit a step inthe process of cell wall synthesis, and in general in the synthesis ofbacterial peptidoglycan. Cell wall synthesis inhibitors include β-lactamantibiotics, natural penicillins, semi-synthetic penicillins,ampicillin, clavulanic acid, cephalolsporins, and bacitracin.

The β-lactams are antibiotics containing a four-membered β-lactam ringwhich inhibits the last step of peptidoglycan synthesis. β-lactamantibiotics can be synthesized or natural. The β-lactam antibioticsproduced by penicillium are the natural penicillins, such as penicillinG or penicillin V. These are produced by fermentation of Penicilliumchrysogenum. The natural penicillins have a narrow spectrum of activityand are generally effective against Streptococcus, Gonococcus, andStaphylococcus. Other types of natural penicillins, which are alsoeffective against gram-positive bacteria, include penicillins F, X, K,and O.

Semi-synthetic penicillins are generally modifications of the molecule6-aminopenicillanic acid produced by a mold. The 6-aminopenicillanicacid can be modified by addition of side chains which producepenicillins having broader spectrums of activity than naturalpenicillins or various other advantageous properties. Some types ofsemi-synthetic penicillins have broad spectrums against gram-positiveand gram-negative bacteria, but are inactivated by penicillinase. Thesesemi-synthetic penicillins include ampicillin, carbenicillin, oxacillin,azlocillin, mezlocillin, and piperacillin. Other types of semi-syntheticpenicillins have narrower activities against gram-positive bacteria, buthave developed properties such that they are not inactivated bypenicillinase. These include, for instance, methicillin, dicloxacillin,and nafcillin. Some of the broad spectrum semi-synthetic penicillins canbe used in combination with β-lactamase inhibitors, such as clavulanicacids and sulbactam. The β-lactamase inhibitors do not haveanti-microbial action but they function to inhibit penicillinase, thusprotecting the semi-synthetic penicillin from degradation.

Another type of β-lactam antibiotic is the cephalolsporins. They aresensitive to degradation by bacterial β-lactamases, and thus, are notalways effective alone. Cephalolsporins, however, are resistant topenicillinase. They are effective against a variety of gram-positive andgram-negative bacteria. Cephalolsporins include, but are not limited to,cephalothin, cephapirin, cephalexin, cefamandole, cefaclor, cefazolin,cefuroxine, cefoxitin, cefotaxime, cefsulodin, cefetamet, cefixime,ceftriaxone, cefoperazone, ceftazidine, and moxalactam.

Bacitracin is another class of antibiotics which inhibit cell wallsynthesis, by inhibiting the release of muropeptide subunits orpeptidoglycan from the molecule that delivers the subunit to the outsideof the membrane. Although bacitracin is effective against gram-positivebacteria, its use is limited in general to topical administrationbecause of its high toxicity.

Carbapenems are another broad-spectrum β-lactam antibiotic, which iscapable of inhibiting cell wall synthesis. Examples of carbapenemsinclude, but are not limited to, imipenems. Monobactams are alsobroad-spectrum β-lactam antibiotics, and include, euztreonam. Anantibiotic produced by Streptomyces, vancomycin, is also effectiveagainst gram-positive bacteria by inhibiting cell membrane synthesis.

Another class of anti-bacterial agents is the anti-bacterial agents thatare cell membrane inhibitors. These compounds disorganize the structureor inhibit the function of bacterial membranes. One problem withanti-bacterial agents that are cell membrane inhibitors is that they canproduce effects in eukaryotic cells as well as bacteria because of thesimilarities in phospholipids in bacterial and eukaryotic membranes.Thus these compounds are rarely specific enough to permit thesecompounds to be used systemically and prevent the use of high doses forlocal administration.

One clinically useful cell membrane inhibitor is Polymyxin. Polymyxinsinterfere with membrane function by binding to membrane phospholipids.Polymyxin is effective mainly against Gram-negative bacteria and isgenerally used in severe Pseudomonas infections or Pseudomonasinfections that are resistant to less toxic antibiotics. The severe sideeffects associated with systemic administration of this compound includedamage to the kidney and other organs.

Other cell membrane inhibitors include Amphotericin B and Nystatin whichare anti-fungal agents used predominantly in the treatment of systemicfungal infections and Candida yeast infections. Imidazoles are anotherclass of antibiotic that is a cell membrane inhibitor. Imidazoles areused as anti-bacterial agents as well as anti-fungal agents, e.g., usedfor treatment of yeast infections, dermatophytic infections, andsystemic fungal infections. Imidazoles include but are not limited toclotrimazole, miconazole, ketoconazole, itraconazole, and fluconazole.

Many anti-bacterial agents are protein synthesis inhibitors. Thesecompounds prevent bacteria from synthesizing structural proteins andenzymes and thus cause inhibition of bacterial cell growth or functionor cell death. In general these compounds interfere with the processesof transcription or translation. Anti-bacterial agents that blocktranscription include but are not limited to Rifampins and Ethambutol.Rifampins, which inhibit the enzyme RNA polymerase, have a broadspectrum activity and are effective against gram-positive andgram-negative bacteria as well as Mycobacterium tuberculosis. Ethambutolis effective against Mycobacterium tuberculosis.

Anti-bacterial agents which block translation interfere with bacterialribosomes to prevent mRNA from being translated into proteins. Ingeneral this class of compounds includes but is not limited totetracyclines, chloramphenicol, the macrolides (e.g., erythromycin) andthe aminoglycosides (e.g., streptomycin).

The aminoglycosides are a class of antibiotics which are produced by thebacterium Streptomyces, such as, for instance streptomycin, kanamycin,tobramycin, amikacin, and gentamicin. Aminoglycosides have been usedagainst a wide variety of bacterial infections caused by Gram-positiveand Gram-negative bacteria. Streptomycin has been used extensively as aprimary drug in the treatment of tuberculosis. Gentamicin is usedagainst many strains of Gram-positive and Gram-negative bacteria,including Pseudomonas infections, especially in combination withTobramycin. Kanamycin is used against many Gram-positive bacteria,including penicillin-resistant Staphylococci. One side effect ofaminoglycosides that has limited their use clinically is that at dosageswhich are essential for efficacy, prolonged use has been shown to impairkidney function and cause damage to the auditory nerves leading todeafness.

Another type of translation inhibitor anti-bacterial agent is thetetracyclines. The tetracyclines are a class of antibiotics that arebroad-spectrum and are effective against a variety of gram-positive andgram-negative bacteria. Examples of tetracyclines include tetracycline,minocycline, doxycycline, and chlortetracycline. They are important forthe treatment of many types of bacteria but are particularly importantin the treatment of Lyme disease. As a result of their low toxicity andminimal direct side effects, the tetracyclines have been overused andmisused by the medical community, leading to problems. For instance,their overuse has led to widespread development of resistance.

Anti-bacterial agents such as the macrolides bind reversibly to the 50 Sribosomal subunit and inhibit elongation of the protein by peptidyltransferase or prevent the release of uncharged tRNA from the bacterialribosome or both. These compounds include erythromycin, roxithromycin,clarithromycin, oleandomycin, and azithromycin. Erythromycin is activeagainst most Gram-positive bacteria, Neisseria, Legionella andHaemophilus, but not against the Enterobacteriaceae. Lincomycin andclindamycin, which block peptide bond formation during proteinsynthesis, are used against gram-positive bacteria.

Another type of translation inhibitor is chloramphenicol.Chloramphenicol binds the 70 S ribosome inhibiting the bacterial enzymepeptidyl transferase thereby preventing the growth of the polypeptidechain during protein synthesis. One serious side effect associated withchloramphenicol is aplastic anemia. Aplastic anemia develops at doses ofchloramphenicol which are effective for treating bacteria in a smallproportion (1/50,000) of patients. Chloramphenicol which was once ahighly prescribed antibiotic is now seldom uses as a result of thedeaths from anemia. Because of its effectiveness it is still used inlife-threatening situations (e.g., typhoid fever).

Some anti-bacterial agents disrupt nucleic acid synthesis or function,e.g., bind to DNA or RNA so that their messages cannot be read. Theseinclude but are not limited to quinolones and co-trimoxazole, bothsynthetic chemicals and rifamycins, a natural or semi-syntheticchemical. The quinolones block bacterial DNA replication by inhibitingthe DNA gyrase, the enzyme needed by bacteria to produce their circularDNA. They are broad spectrum and examples include norfloxacin,ciprofloxacin, enoxacin, nalidixic acid and temafloxacin. Nalidixic acidis a bactericidal agent that binds to the DNA gyrase enzyme(topoisomerase) which is essential for DNA replication and allowssupercoils to be relaxed and reformed, inhibiting DNA gyrase activity.The main use of nalidixic acid is in treatment of lower urinary tractinfections (UTI) because it is effective against several types ofGram-negative bacteria such as E. coli, Enterobacter aerogenes, K.pneumoniae and Proteus species which are common causes of UTI.Co-trimoxazole is a combination of sulfamethoxazole and trimethoprim,which blocks the bacterial synthesis of folic acid needed to make DNAnucleotides. Rifampicin is a derivative of rifamycin that is activeagainst Gram-positive bacteria (including Mycobacterium tuberculosis andmeningitis caused by Neisseria meningitidis) and some Gram-negativebacteria. Rifampicin binds to the beta subunit of the polymerase andblocks the addition of the first nucleotide which is necessary toactivate the polymerase, thereby blocking mRNA synthesis.

Another class of anti-bacterial agents is compounds that function ascompetitive inhibitors of bacterial enzymes. The competitive inhibitorsare mostly all structurally similar to a bacterial growth factor andcompete for binding but do not perform the metabolic function in thecell. These compounds include sulfonamides and chemically modified formsof sulfanilamide which have even higher and broader antibacterialactivity. The sulfonamides (e.g., gantrisin and trimethoprim) are usefulfor the treatment of Streptococcus pneumoniae, beta-hemolyticstreptococci and E. coli, and have been used in the treatment ofuncomplicated UTI caused by E. coli, and in the treatment ofmeningococcal meningitis.

Anti-viral agents are compounds which prevent infection of cells byviruses or replication of the virus within the cell. There are manyfewer antiviral drugs than antibacterial drugs because the process ofviral replication is so closely related to DNA replication within thehost cell, that non-specific antiviral agents would often be toxic tothe host. There are several stages within the process of viral infectionwhich can be blocked or inhibited by antiviral agents. These stagesinclude, attachment of the virus to the host cell (immunoglobulin orbinding peptides), uncoating of the virus (e.g. amantadine), synthesisor translation of viral mRNA (e.g. interferon), replication of viral RNAor DNA (e.g. nucleoside analogues), maturation of new virus proteins(e.g. protease inhibitors), and budding and release of the virus.

Another category of anti-viral agents are nucleoside analogues.Nucleoside analogues are synthetic compounds which are similar tonucleosides, but which have an incomplete or abnormal deoxyribose orribose group. Once the nucleoside analogues are in the cell, they arephosphorylated, producing the triphosphate form which competes withnormal nucleotides for incorporation into the viral DNA or RNA. Once thetriphosphate form of the nucleoside analogue is incorporated into thegrowing nucleic acid chain, it causes irreversible association with theviral polymerase and thus chain termination. Nucleoside analoguesinclude, but are not limited to, acyclovir (used for the treatment ofherpes simplex virus and varicella-zoster virus), gancyclovir (usefulfor the treatment of cytomegalovirus), idoxuridine, ribavirin (usefulfor the treatment of respiratory syncitial virus), dideoxyinosine,dideoxycytidine, and zidovudine (azidothymidine).

Another class of anti-viral agents includes cytokines such asinterferons. The interferons are cytokines which are secreted byvirus-infected cells as well as immune cells. The interferons functionby binding to specific receptors on cells adjacent to the infectedcells, causing the change in the cell which protects it from infectionby the virus. α and β-interferon also induce the expression of Class Iand Class II MHC molecules on the surface of infected cells, resultingin increased antigen presentation for host immune cell recognition. αand β-interferons are available as recombinant forms and have been usedfor the treatment of chronic hepatitis B and C infection. At the dosageswhich are effective for anti-viral therapy, interferons have severe sideeffects such as fever, malaise and weight loss.

Immunoglobulin therapy is used for the prevention of viral infection.Immunoglobulin therapy for viral infections is different from bacterialinfections, because rather than being antigen-specific, theimmunoglobulin therapy functions by binding to extracellular virions andpreventing them from attaching to and entering cells which aresusceptible to the viral infection. The therapy is useful for theprevention of viral infection for the period of time that the antibodiesare present in the host. In general there are two types ofimmunoglobulin therapies, normal immune globulin therapy andhyper-immune globulin therapy. Normal immune globulin therapy utilizes aantibody product which is prepared from the serum of normal blood donorsand pooled. This pooled product contains low titers of antibody to awide range of human viruses, such as hepatitis A, parvovirus,enterovirus (especially in neonates). Hyper-immune globulin therapyutilizes antibodies which are prepared from the serum of individuals whohave high titers of an antibody to a particular virus. Those antibodiesare then used against a specific virus. Examples of hyper-immuneglobulins include zoster immune globulin (useful for the prevention ofvaricella in immunocompromised children and neonates), human rabiesimmune globulin (useful in the post-exposure prophylaxis of a subjectbitten by a rabid animal), hepatitis B immune globulin (useful in theprevention of hepatitis B virus, especially in a subject exposed to thevirus), and RSV immune globulin (useful in the treatment of respiratorysyncitial virus infections).

Anti-fungal agents are useful for the treatment and prevention ofinfective fungi. Anti-fungal agents are sometimes classified by theirmechanism of action. Some anti-fungal agents function as cell wallinhibitors by inhibiting glucose synthase. These include, but are notlimited to, basiungin/ECB. Other anti-fungal agents function bydestabilizing membrane integrity. These include, but are not limited to,imidazoles, such as clotrimazole, sertaconzole, fluconazole,itraconazole, ketoconazole, miconazole, and voriconacole, as well as FK463, amphotericin B, BAY 38-9502, MK 991, pradimicin, UK 292,butenafine, and terbinafine. Other anti-fungal agents function bybreaking down chitin (e.g., chitinase) or immunosuppression (501 cream).

Parasiticides are agents that kill parasites directly. Such compoundsare known in the art and are generally commercially available. Examplesof parasiticides useful for human administration include but are notlimited to albendazole, amphotericin B, benznidazole, bithionol,chloroquine HCl, chloroquine phosphate, clindamycin, dehydroemetine,diethylcarbamazine, diloxanide furoate, eflornithine, furazolidaone,glucocorticoids, halofantrine, iodoquinol, ivermectin, mebendazole,mefloquine, meglumine antimoniate, melarsoprol, metrifonate,metronidazole, niclosamide, nifurtimox, oxamniquine, paromomycin,pentamidine isethionate, piperazine, praziquantel, primaquine phosphate,proguanil, pyrantel pamoate, pyrimethanmine-sulfonamides,pyrimethanmine-sulfadoxine, quinacrine HCl, quinine sulfate, quinidinegluconate, spiramycin, stibogluconate sodium (sodium antimonygluconate), suramin, tetracycline, doxycycline, thiabendazole,tinidazole, trimethroprim-sulfamethoxazole, and tryparsamide.

The ORNs are also useful for treating and preventing autoimmune disease.Autoimmune disease is a class of diseases in which an subject's ownantibodies react with host tissue or in which immune effector T cellsare autoreactive to endogenous self peptides and cause destruction oftissue. Thus an immune response is mounted against a subject's ownantigens, referred to as self antigens. Autoimmune diseases include butare not limited to rheumatoid arthritis, Crohn's disease, multiplesclerosis, systemic lupus erythematosus (SLE), autoimmuneencephalomyelitis, myasthenia gravis (MG), Hashimoto's thyroiditis,Goodpasture's syndrome, pemphigus (e.g., pemphigus vulgaris), Grave'sdisease, autoimmune hemolytic anemia, autoimmune thrombocytopenicpurpura, scleroderma with anti-collagen antibodies, mixed connectivetissue disease, polymyositis, pernicious anemia, idiopathic Addison'sdisease, autoimmune-associated infertility, glomerulonephritis (e.g.,crescentic glomerulonephritis, proliferative glomerulonephritis),bullous pemphigoid, Sjögren's syndrome, insulin resistance, andautoimmune diabetes mellitus.

A “self-antigen” as used herein refers to an antigen of a normal hosttissue. Normal host tissue does not include cancer cells. Thus an immuneresponse mounted against a self-antigen, in the context of an autoimmunedisease, is an undesirable immune response and contributes todestruction and damage of normal tissue, whereas an immune responsemounted against a cancer antigen is a desirable immune response andcontributes to the destruction of the tumor or cancer. Thus, in someaspects of the invention aimed at treating autoimmune disorders it isnot recommended that the ORN be administered with self antigens,particularly those that are the targets of the autoimmune disorder.

In other instances, the ORN may be delivered with low doses ofself-antigens. A number of animal studies have demonstrated that mucosaladministration of low doses of antigen can result in a state of immunehyporesponsiveness or “tolerance.” The active mechanism appears to be acytokine-mediated immune deviation away from a Th1 towards apredominantly Th2 and Th3 (i.e., TGF-β dominated) response. The activesuppression with low dose antigen delivery can also suppress anunrelated immune response (bystander suppression) which is ofconsiderable interest in the therapy of autoimmune diseases, forexample, rheumatoid arthritis and SLE. Bystander suppression involvesthe secretion of Th1-counter-regulatory, suppressor cytokines in thelocal environment where proinflammatory and Th1 cytokines are releasedin either an antigen-specific or antigen-nonspecific manner. “Tolerance”as used herein is used to refer to this phenomenon. Indeed, oraltolerance has been effective in the treatment of a number of autoimmunediseases in animals including: experimental autoimmune encephalomyelitis(EAE), experimental autoimmune myasthenia gravis, collagen-inducedarthritis (CIA), and insulin-dependent diabetes mellitus. In thesemodels, the prevention and suppression of autoimmune disease isassociated with a shift in antigen-specific humoral and cellularresponses from a Th1 to Th2/Th3 response.

The compositions and methods of the invention can be used alone or inconjunction with other agents and methods useful for the treatment ofcancer. In one aspect the invention provides a method of treating asubject having a cancer. The method according to this aspect of theinvention includes the step of administering to a subject having acancer an effective amount of a composition of the invention to treatthe subject.

In one aspect the invention provides a method of treating a subjecthaving a cancer. The method according to this aspect of the inventionincludes the step of administering to a subject having a cancer aneffective amount of the composition of the invention and an anti-cancertherapy to treat the subject.

In one aspect the invention provides a use of an immunostimulatory ORNof the invention for the preparation of a medicament for treating cancerin a subject.

In one aspect the invention provides a composition useful for thetreatment of cancer. The composition according to this aspect includesan immunostimulatory ORN of the invention and a cancer medicament.

A subject having a cancer is a subject that has detectable cancerouscells. The cancer may be a malignant or non-malignant cancer. “Cancer”as used herein refers to an uncontrolled growth of cells whichinterferes with the normal functioning of the bodily organs and systems.Cancers which migrate from their original location and seed vital organscan eventually lead to the death of the subject through the functionaldeterioration of the affected organs. Hemopoietic cancers, such asleukemia, are able to outcompete the normal hemopoietic compartments ina subject, thereby leading to hemopoietic failure (in the form ofanemia, thrombocytopenia and neutropenia) ultimately causing death.

A metastasis is a region of cancer cells, distinct from the primarytumor location, resulting from the dissemination of cancer cells fromthe primary tumor to other parts of the body. At the time of diagnosisof the primary tumor mass, the subject may be monitored for the presenceof metastases. Metastases are most often detected through the sole orcombined use of magnetic resonance imaging (MRI) scans, computedtomography (CT) scans, blood and platelet counts, liver functionstudies, chest X-rays and bone scans in addition to the monitoring ofspecific symptoms.

Cancers include, but are not limited to, basal cell carcinoma, biliarytract cancer; bladder cancer; bone cancer; brain and central nervoussystem (CNS) cancer; breast cancer; cervical cancer; choriocarcinoma;colon and rectum cancer; connective tissue cancer; cancer of thedigestive system; endometrial cancer; esophageal cancer; eye cancer;cancer of the head and neck; intra-epithelial neoplasm; kidney cancer;larynx cancer; leukemia; liver cancer; lung cancer (e.g. small cell andnon-small cell); lymphoma including Hodgkin's and Non-Hodgkin'slymphoma; melanoma; myeloma; neuroblastoma; oral cavity cancer (e.g.,lip, tongue, mouth, and pharynx); ovarian cancer; pancreatic cancer;prostate cancer; retinoblastoma; rhabdomyosarcoma; rectal cancer; cancerof the respiratory system; sarcoma; skin cancer; stomach cancer;testicular cancer; thyroid cancer; uterine cancer; cancer of the urinarysystem, as well as other carcinomas, adenocarcinomas, and sarcomas.

The immunostimulatory composition of the invention may also beadministered in conjunction with an anti-cancer therapy. Anti-cancertherapies include cancer medicaments, radiation, and surgicalprocedures. As used herein, a “cancer medicament” refers to an agentwhich is administered to a subject for the purpose of treating a cancer.As used herein, “treating cancer” includes preventing the development ofa cancer, reducing the symptoms of cancer, and/or inhibiting the growthof an established cancer. In other aspects, the cancer medicament isadministered to a subject at risk of developing a cancer for the purposeof reducing the risk of developing the cancer. Various types ofmedicaments for the treatment of cancer are described herein. For thepurpose of this specification, cancer medicaments are classified aschemotherapeutic agents, immunotherapeutic agents, cancer vaccines,hormone therapy, and biological response modifiers.

The chemotherapeutic agent may be selected from the group consisting ofmethotrexate, vincristine, adriamycin, cisplatin, non-sugar containingchloroethylnitrosoureas, 5-fluorouracil, mitomycin C, bleomycin,doxorubicin, dacarbazine, taxol, fragyline, Meglamine GLA, valrubicin,carmustaine and poliferposan, MMI270, BAY 12-9566, RAS farnesyltransferase inhibitor, farnesyl transferase inhibitor, MMP,MTA/LY231514, LY264618/Lometexol, Glamolec, CI-994, TNP-470,Hycamtin/Topotecan, PKC412, Valspodar/PSC833, Novantrone/Mitroxantrone,Metaret/Suramin, Batimastat, E7070, BCH-4556, CS-682, 9-AC, AG3340,AG3433, Incel/VX-710, VX-853, ZD0101, ISI641, ODN 698, TA2516/Marmistat, BB2516/Marmistat, CDP 845, D2163, PD183805, DX8951f,Lemonal DP 2202, FK 317, picibanil/OK-432, AD 32/Valrubicin,Metastron/strontium derivative, Temodal/Temozolomide, Evacet/liposomaldoxorubicin, Yewtaxan/Paclitaxel, Taxol/Paclitaxel, Xeload/Capecitabine,Furtulon/Doxifluridine, Cyclopax/oral paclitaxel, Oral Taxoid,SPU-077/Cisplatin, HMR 1275/Flavopiridol, CP-358 (774)/EGFR, CP-609(754)/RAS oncogene inhibitor, BMS-182751/oral platinum,UFT(Tegafur/Uracil), Ergamisol/Levamisole, Eniluracil/776C85/5FUenhancer, Campto/Levamisole, Carnptosar/Irinotecan, Tumodex/Ralitrexed,Leustatin/Cladribine, Paxex/Paclitaxel, Doxil/liposomal doxorubicin,Caelyx/liposomal doxorubicin, Fludara/Fludarabine,Pharmarubicin/Epirubicin, DepoCyt, ZD1839, LU 79553/Bis-Naphtalimide, LU103793/Dolastain, Caetyx/liposomal doxorubicin, Gemzar/Gemcitabine, ZD0473/Anormed, YM 116, Iodine seeds, CDK4 and CDK2 inhibitors, PARPinhibitors, D4809/Dexifosamide, Ifes/Mesnex/Ifosamide, Vumon/Teniposide,Paraplatin/Carboplatin, Plantinol/cisplatin, Vepeside/Etoposide, ZD9331, Taxotere/Docetaxel, prodrug of guanine arabinoside, Taxane Analog,nitrosoureas, alkylating agents such as melphelan and cyclophosphamide,Aminoglutethimide, Asparaginase, Busulfan, Carboplatin, Chlorombucil,Cytarabine HCI, Dactinomycin, Daunorubicin HCl, Estramustine phosphatesodium, Etoposide (VP16-213), Floxuridine, Fluorouracil (5-FU),Flutamide, Hydroxyurea (hydroxycarbamide), Ifosfamide, InterferonAlfa-2a, Alfa-2b, Leuprolide acetate (LHRH-releasing factor analogue),Lomustine (CCNU), Mechlorethamine HCl (nitrogen mustard),Mercaptopurine, Mesna, Mitotane (o.p′-DDD), Mitoxantrone HCl,Octreotide, Plicamycin, Procarbazine HCl, Streptozocin, Tamoxifencitrate, Thioguanine, Thiotepa, Vinblastine sulfate, Amsacrine (m-AMSA),Azacitidine, Erthropoietin, Hexamethylmelamine (HMM), Interleukin 2,Mitoguazone (methyl-GAG; methyl glyoxal bis-guanylhydrazone; MGBG),Pentostatin (2′deoxycoformycin), Semustine (methyl-CCNU), Teniposide(VM-26) and Vindesine sulfate, but it is not so limited.

The immunotherapeutic agent may be selected from the group consisting of3622W94, 4B5, ANA Ab, anti-FLK-2, anti-VEGF, ATRAGEN, AVASTIN(bevacizumab; Genentech), BABS, BEC2, BEXXAR (tositumomab;GlaxoSmithKline), C225, CAMPATH (alemtuzumab; Genzyme Corp.), CEACIDE,CMA 676, EMD-72000, ERBITUX (cetuximab; ImClone Systems, Inc.),Gliomab-H, GNI-250, HERCEPTIN (trastuzumab; Genentech), IDEC-Y2B8,ImmuRAIT-CEA, ior c5, ior egf.r3, ior t6, LDP-03, LymphoCide, MDX-11,MDX-22, MDX-210, MDX-220, MDX-260, MDX-447, MELIMMUNE-1, MELIMMUNE-2,Monopharm-C, NovoMAb-G2, Oncolym, OV103, Ovarex, Panorex, Pretarget,Quadramet, Ributaxin, RITUXAN (rituximab; Genentech), SMART 1D10 Ab,SMART ABL 364 Ab, SMART M195, TNT, and ZENAPAX (daclizumab; Roche), butit is not so limited.

The cancer vaccine may be selected from the group consisting of EGF,Anti-idiotypic cancer vaccines, Gp75 antigen, GMK melanoma vaccine, MGVganglioside conjugate vaccine, Her2/neu, Ovarex, M-Vax, O-Vax, L-Vax,STn-KHL theratope, BLP25 (MUC-1), liposomal idiotypic vaccine, Melacine,peptide antigen vaccines, toxin/antigen vaccines, MVA-based vaccine,PACIS, BCG vacine, TA-HPV, TA-CIN, DISC-virus and ImmuCyst/TheraCys, butit is not so limited.

The compositions and methods of the invention can be used alone or inconjunction with other agents and methods useful for the treatment ofallergy. In one aspect the invention provides a method of treating asubject having an allergic condition. The method according to thisaspect of the invention includes the step of administering to a subjecthaving an allergic condition an effective amount of a composition of theinvention to treat the subject.

In one aspect the invention provides a method of treating a subjecthaving an allergic condition. The method according to this aspect of theinvention includes the step of administering to a subject having anallergic condition an effective amount of the composition of theinvention and an anti-allergy therapy to treat the subject.

In one aspect the invention provides a use of an immunostimulatory ORNof the invention for the preparation of a medicament for treating anallergic condition in a subject.

In one aspect the invention provides a composition useful for thetreatment of an allergic condition. The composition according to thisaspect includes an immunostimulatory ORN of the invention and an allergymedicament.

A “subject having an allergic condition” shall refer to a subject thatis currently experiencing or has previously experienced an allergicreaction in response to an allergen.

An “allergic condition” or “allergy” refers to acquired hypersensitivityto a substance (allergen). Allergic conditions include but are notlimited to eczema, allergic rhinitis or coryza, hay fever, allergicconjunctivitis, bronchial asthma, urticaria (hives) and food allergies,other atopic conditions including atopic dermatitis; anaphylaxis; drugallergy; and angioedema.

Allergy is typically an episodic condition associated with theproduction of antibodies from a particular class of immunoglobulin, IgE,against allergens. The development of an IgE-mediated response to commonaeroallergens is also a factor which indicates predisposition towardsthe development of asthma. If an allergen encounters a specific IgEwhich is bound to an IgE Fc receptor (FcεR) on the surface of a basophil(circulating in the blood) or mast cell (dispersed throughout solidtissue), the cell becomes activated, resulting in the production andrelease of mediators such as histamine, serotonin, and lipid mediators.

An allergic reaction occurs when tissue-sensitizing immunoglobulin ofthe IgE type reacts with foreign allergen. The IgE antibody is bound tomast cells and/or basophils, and these specialized cells releasechemical mediators (vasoactive amines) of the allergic reaction whenstimulated to do so by allergens bridging the ends of the antibodymolecule. Histamine, platelet activating factor, arachidonic acidmetabolites, and serotonin are among the best known mediators ofallergic reactions in man. Histamine and the other vasoactive amines arenormally stored in mast cells and basophil leukocytes. The mast cellsare dispersed throughout animal tissue and the basophils circulatewithin the vascular system. These cells manufacture and store histaminewithin the cell unless the specialized sequence of events involving IgEbinding occurs to trigger its release.

Symptoms of an allergic reaction vary, depending on the location withinthe body where the IgE reacts with the antigen. If the reaction occursalong the respiratory epithelium, the symptoms generally are sneezing,coughing and asthmatic reactions. If the interaction occurs in thedigestive tract, as in the case of food allergies, abdominal pain anddiarrhea are common. Systemic allergic reactions, for example followinga bee sting or administration of penicillin to an allergic subject, canbe severe and often life-threatening.

Allergy is associated with a Th2-type of immune response, which ischaracterized at least in part by Th2 cytokines IL-4 and IL-5, as wellas antibody isotype switching to IgE. Th1 and Th2 immune responses aremutually counter-regulatory, so that skewing of the immune responsetoward a Th1-type of immune response can prevent or ameliorate aTh2-type of immune response, including allergy. The immunostimulatoryORN of the invention are therefore useful by themselves to treat asubject having an allergic condition because the immunostimulatory ORNcan skew the immune response toward a Th1-type of immune response.Alternatively or in addition, the immunostimulatory ORN of the inventioncan be used in combination with an allergen to treat a subject having anallergic condition.

The immunostimulatory composition of the invention may also beadministered in conjunction with an anti-allergy therapy. Conventionalmethods for treating or preventing allergy have involved the use ofallergy medicaments or desensitization therapies. Some evolvingtherapies for treating or preventing allergy include the use ofneutralizing anti-IgE antibodies. Anti-histamines and other drugs whichblock the effects of chemical mediators of the allergic reaction help toregulate the severity of the allergic symptoms but do not prevent theallergic reaction and have no effect on subsequent allergic responses.Desensitization therapies are performed by giving small doses of anallergen, usually by injection under the skin, in order to induce anIgG-type response against the allergen. The presence of IgG antibodyhelps to neutralize the production of mediators resulting from theinduction of IgE antibodies, it is believed. Initially, the subject istreated with a very low dose of the allergen to avoid inducing a severereaction and the dose is slowly increased. This type of therapy isdangerous because the subject is actually administered the compoundswhich cause the allergic response and severe allergic reactions canresult.

Allergy medicaments include, but are not limited to, anti-histamines,corticosteroids, and prostaglandin inducers. Anti-histamines arecompounds which counteract histamine released by mast cells orbasophils. These compounds are well known in the art and commonly usedfor the treatment of allergy. Anti-histamines include, but are notlimited to, acrivastine, astemizole, azatadine, azelastine, betatastine,brompheniramine, buclizine, cetirizine, cetirizine analogues,chlorpheniramine, clemastine, CS 560, cyproheptadine, desloratadine,dexchlorpheniramine, ebastine, epinastine, fexofenadine, HSR 609,hydroxyzine, levocabastine, loratidine, methscopolamine, mizolastine,norastemizole, phenindamine, promethazine, pyrilamine, terfenadine, andtranilast.

Corticosteroids include, but are not limited to, methylprednisolone,prednisolone, prednisone, beclomethasone, budesonide, dexamethasone,flunisolide, fluticasone propionate, and triamcinolone. Althoughdexamethasone is a corticosteroid having anti-inflammatory action, it isnot regularly used for the treatment of allergy or asthma in an inhaledform because it is highly absorbed and it has long-term suppressive sideeffects at an effective dose. Dexamethasone, however, can be usedaccording to the invention for treating allergy or asthma because whenadministered in combination with a composition of the invention it canbe administered at a low dose to reduce the side effects. Some of theside effects associated with corticosteroid use include cough,dysphonia, oral thrush (candidiasis), and in higher doses, systemiceffects, such as adrenal suppression, glucose intolerance, osteoporosis,aseptic necrosis of bone, cataract formation, growth suppression,hypertension, muscle weakness, skin thinning, and easy bruising. Barnes& Peterson (1993) Am Rev Respir Dis 148:S1-S26; and Kamada A K et al.(1996) Am J Respir Crit Care Med 153:1739-48.

The compositions and methods of the invention can be used alone or inconjunction with other agents and methods useful for the treatment ofasthma. In one aspect the invention provides a method of treating asubject having asthma. The method according to this aspect of theinvention includes the step of administering to a subject having asthmaan effective amount of a composition of the invention to treat thesubject.

In one aspect the invention provides a method of treating a subjecthaving asthma. The method according to this aspect of the inventionincludes the step of administering to a subject having asthma aneffective amount of the composition of the invention and an anti-asthmatherapy to treat the subject.

In one aspect the invention provides a use of an immunostimulatory ORNof the invention for the preparation of a medicament for treating asthmain a subject.

In one aspect the invention provides a composition useful for thetreatment of asthma. The composition according to this aspect includesan immunostimulatory ORN of the invention and an asthma medicament.

“Asthma” as used herein refers to a disorder of the respiratory systemcharacterized by inflammation and narrowing of the airways, andincreased reactivity of the airways to inhaled agents. Asthma isfrequently, although not exclusively, associated with an atopic orallergic condition. Symptoms of asthma include recurrent episodes ofwheezing, breathlessness, chest tightness, and coughing, resulting fromairflow obstruction. Airway inflammation associated with asthma can bedetected through observation of a number of physiological changes, suchas, denudation of airway epithelium, collagen deposition beneathbasement membrane, edema, mast cell activation, inflammatory cellinfiltration, including neutrophils, eosinophils, and lymphocytes. As aresult of the airway inflammation, asthma patients often experienceairway hyper-responsiveness, airflow limitation, respiratory symptoms,and disease chronicity. Airflow limitations include acutebronchoconstriction, airway edema, mucous plug formation, and airwayremodeling, features which often lead to bronchial obstruction. In somecases of asthma, sub-basement membrane fibrosis may occur, leading topersistent abnormalities in lung function.

Research over the past several years has revealed that asthma likelyresults from complex interactions among inflammatory cells, mediators,and other cells and tissues resident in the airways. Mast cells,eosinophils, epithelial cells, macrophage, and activated T cells allplay an important role in the inflammatory process associated withasthma. Djukanovic R et al. (1990) Am Rev Respir Dis 142:434-457. It isbelieved that these cells can influence airway function throughsecretion of preformed and newly synthesized mediators which can actdirectly or indirectly on the local tissue. It has also been recognizedthat subpopulations of T lymphocytes (Th2) play an important role inregulating allergic inflammation in the airway by releasing selectivecytokines and establishing disease chronicity. Robinson D S et al.(1992) N Engl J Med 326:298-304.

Asthma is a complex disorder which arises at different stages indevelopment and can be classified based on the degree of symptoms asacute, subacute, or chronic. An acute inflammatory response isassociated with an early recruitment of cells into the airway. Thesubacute inflammatory response involves the recruitment of cells as wellas the activation of resident cells causing a more persistent pattern ofinflammation. Chronic inflammatory response is characterized by apersistent level of cell damage and an ongoing repair process, which mayresult in permanent abnormalities in the airway.

A “subject having asthma” is a subject that has a disorder of therespiratory system characterized by inflammation and narrowing of theairways and increased reactivity of the airways to inhaled agents.Factors associated with initiation of asthma include, but are notlimited to, allergens, cold temperature, exercise, viral infections, andSO₂.

As mentioned above, asthma may be associated with a Th2-type of immuneresponse, which is characterized at least in part by Th2 cytokines IL-4and IL-5, as well as antibody isotype switching to IgE. Th1 and Th2immune responses are mutually counter-regulatory, so that skewing of theimmune response toward a Th1-type of immune response can prevent orameliorate a Th2-type of immune response, including allergy. Themodified oligoribonucleotide analogs of the invention are thereforeuseful by themselves to treat a subject having asthma because theanalogs can skew the immune response toward a Th1-type of immuneresponse. Alternatively or in addition, the modified oligoribonucleotideanalogs of the invention can be used in combination with an allergen totreat a subject having asthma.

The immunostimulatory composition of the invention may also beadministered in conjunction with an asthma therapy. Conventional methodsfor treating or preventing asthma have involved the use of anti-allergytherapies (described above) and a number of other agents, includinginhaled agents.

Medications for the treatment of asthma are generally separated into twocategories, quick-relief medications and long-term control medications.Asthma patients take the long-term control medications on a daily basisto achieve and maintain control of persistent asthma. Long-term controlmedications include anti-inflammatory agents such as corticosteroids,chromolyn sodium and nedocromil; long-acting bronchodilators, such aslong-acting β₂-agonists and methylxanthines; and leukotriene modifiers.The quick-relief medications include short-acting β₂ agonists,anti-cholinergics, and systemic corticosteroids. There are many sideeffects associated with each of these drugs and none of the drugs aloneor in combination is capable of preventing or completely treatingasthma.

Asthma medicaments include, but are not limited, PDE-4 inhibitors,bronchodilator/beta-2 agonists, K+ channel openers, VLA-4 antagonists,neurokin antagonists, thromboxane A2 (TXA2) synthesis inhibitors,xanthines, arachidonic acid antagonists, 5 lipoxygenase inhibitors, TXA2receptor antagonists, TXA2 antagonists, inhibitor of 5-lipox activationproteins, and protease inhibitors.

Bronchodilator/β₂ agonists are a class of compounds which causebronchodilation or smooth muscle relaxation. Bronchodilator/β₂ agonistsinclude, but are not limited to, salmeterol, salbutamol, albuterol,terbutaline, D2522/formoterol, fenoterol, bitolterol, pirbuerolmethylxanthines and orciprenaline. Long-acting β₂ agonists andbronchodilators are compounds which are used for long-term prevention ofsymptoms in addition to the anti-inflammatory therapies. Long-acting β₂agonists include, but are not limited to, salmeterol and albuterol.These compounds are usually used in combination with corticosteroids andgenerally are not used without any inflammatory therapy. They have beenassociated with side effects such as tachycardia, skeletal muscletremor, hypokalemia, and prolongation of QTc interval in overdose.

Methylxanthines, including for instance theophylline, have been used forlong-term control and prevention of symptoms. These compounds causebronchodilation resulting from phosphodiesterase inhibition and likelyadenosine antagonism. Dose-related acute toxicities are a particularproblem with these types of compounds. As a result, routine serumconcentration must be monitored in order to account for the toxicity andnarrow therapeutic range arising from individual differences inmetabolic clearance. Side effects include tachycardia, tachyarrhythmias,nausea and vomiting, central nervous system stimulation, headache,seizures, hematemesis, hyperglycemia and hypokalemia. Short-acting β₂agonists include, but are not limited to, albuterol, bitolterol,pirbuterol, and terbutaline. Some of the adverse effects associated withthe administration of short-acting β₂ agonists include tachycardia,skeletal muscle tremor, hypokalemia, increased lactic acid, headache,and hyperglycemia.

Chromolyn sodium and nedocromil are used as long-term controlmedications for preventing primarily asthma symptoms arising fromexercise or allergic symptoms arising from allergens. These compoundsare believed to block early and late reactions to allergens byinterfering with chloride channel function. They also stabilize mastcell membranes and inhibit activation and release of mediators frominosineophils and epithelial cells. A four to six week period ofadministration is generally required to achieve a maximum benefit.

Anticholinergics are generally used for the relief of acutebronchospasm. These compounds are believed to function by competitiveinhibition of muscarinic cholinergic receptors. Anticholinergicsinclude, but are not limited to, ipratropium bromide. These compoundsreverse only cholinerigically-mediated bronchospasm and do not modifyany reaction to antigen. Side effects include drying of the mouth andrespiratory secretions, increased wheezing in some individuals, andblurred vision if sprayed in the eyes.

The immunostimulatory ORN of the invention may also be useful fortreating airway remodeling. Airway remodeling results from smooth musclecell proliferation and/or submucosal thickening in the airways, andultimately causes narrowing of the airways leading to restrictedairflow. The immunostimulatory ORN of the invention may prevent furtherremodeling and possibly even reduce tissue build-up resulting from theremodeling process.

The immunostimulatory ORN of the invention are also useful for improvingsurvival, differentiation, activation and maturation of dendritic cells.The immunostimulatory oligoribonucleotides have the unique capability topromote cell survival, differentiation, activation and maturation ofdendritic cells.

Immunostimulatory ORN of the invention also increase natural killer celllytic activity and antibody-dependent cellular cytotoxicity (ADCC). ADCCcan be performed using an immunostimulatory ORN in combination with anantibody specific for a cellular target, such as a cancer cell. When theimmunostimulatory ORN is administered to a subject in conjunction withthe antibody, the subject's immune system is induced to kill the tumorcell. The antibodies useful in the ADCC procedure include antibodieswhich interact with a cell in the body. Many such antibodies specificfor cellular targets have been described in the art and many arecommercially available. In one embodiment the antibody is an IgGantibody.

In certain aspects the invention provides a method for enhancing epitopespreading. “Epitope spreading” as used herein refers to thediversification of epitope specificity from an initial focused, dominantepitope-specific immune response, directed against a self or foreignprotein, to subdominant and/or cryptic epitopes on that protein(intramolecular spreading) or other proteins (intermolecular spreading).Epitope spreading results in multiple epitope-specific immune responses.

The immune response consists of an initial magnification phase, whichcan either be deleterious, as in autoimmune disease, or beneficial, asin vaccinations, and a later down-regulatory phase to return the immunesystem to homeostasis and generate memory. Epitope spreading may be animportant component of both phases. The enhancement of epitope spreadingin the setting of a tumor allows the subject's immune system todetermine additional target epitopes, not initially recognized by theimmune system in response to an original therapeutic protocol, whilereducing the possibility of escape variants in the tumor population andthus affect progression of disease.

The oligoribonucleotides of the invention may be useful for promotingepitope spreading in therapeutically beneficial indications such ascancer, viral and bacterial infections, and allergy. The method in oneembodiment includes the steps of administering a vaccine that includesan antigen and an adjuvant to a subject and subsequently administeringto the subject at least two doses of immunostimulatory ORN of theinvention in an amount effective to induce multiple epitope-specificimmune responses. The method in one embodiment includes the steps ofadministering a vaccine that includes a tumor antigen and an adjuvant toa subject and subsequently administering to the subject at least twodoses of immunostimulatory ORN of the invention in an amount effectiveto induce multiple epitope-specific immune responses. The method in oneembodiment involves applying a therapeutic protocol which results inimmune system antigen exposure in a subject, followed by at least twoadministrations of an immunostimulatory oligoribonucleotide of theinvention, to induce multiple epitope-specific immune responses, i.e.,to promote epitope spreading. In various embodiments the therapeuticprotocol is surgery, radiation, chemotherapy, other cancer medicaments,a vaccine, or a cancer vaccine.

The therapeutic protocol may be implemented in conjunction with animmunostimulant, in addition to the subsequent immunostimulant therapy.For instance, when the therapeutic protocol is a vaccine, it may beadministered in conjunction with an adjuvant. The combination of thevaccine and the adjuvant may be a mixture or separate administrations,i.e., injections (i.e., same drainage field). Administration is notnecessarily simultaneous. If non-simultaneous injection is used, thetiming may involve pre-injection of the adjuvant followed by the vaccineformulation.

After the therapeutic protocol is implemented, immunostimulantmonotherapy begins. The optimized frequency, duration, and site ofadministration will depend on the target and other factors, but may forexample be a monthly to bimonthly administration for a period of sixmonths to two years. Alternatively the administration may be on a daily,weekly, or biweekly basis, or the administration may be multiple timesduring a day, week or month. In some instances, the duration ofadministration may depend on the length of therapy, e.g., it may endafter one week, one month, after one year, or after multiple years. Inother instances the monotherapy may be continuous as with an intravenousdrip. The immunostimulant may be administered to a drainage field commonto the target.

For use in therapy, different doses may be necessary for treatment of asubject, depending on activity of the compound, manner ofadministration, purpose of the immunization (i.e., prophylactic ortherapeutic), nature and severity of the disorder, age and body weightof the subject. The administration of a given dose can be carried outboth by single administration in the form of an individual dose unit orelse several smaller dose units. Multiple administration of doses atspecific intervals of weeks or months apart is usual for boostingantigen-specific immune responses.

Combined with the teachings provided herein, by choosing among thevarious active compounds and weighing factors such as potency, relativebioavailability, patient body weight, severity of adverse side-effectsand preferred mode of administration, an effective prophylactic ortherapeutic treatment regimen can be planned which does not causesubstantial toxicity and yet is entirely effective to treat theparticular subject. The effective amount for any particular applicationcan vary depending on such factors as the disease or condition beingtreated, the particular therapeutic agent being administered, the sizeof the subject, or the severity of the disease or condition. One ofordinary skill in the art can empirically determine the effective amountof a particular nucleic acid and/or other therapeutic agent withoutnecessitating undue experimentation.

Subject doses of the compounds described herein typically range fromabout 0.1 μg to 10,000 mg, more typically from about 1 μg/day to 8000mg, and most typically from about 10 μg to 100 μg. Stated in terms ofsubject body weight, typical dosages range from about 0.1 μg to 20mg/kg/day, more typically from about 1 to 10 mg/kg/day, and mosttypically from about 1 to 5 mg/kg/day.

The pharmaceutical compositions containing nucleic acids and/or othercompounds can be administered by any suitable route for administeringmedications. A variety of administration routes are available. Theparticular mode selected will depend, of course, upon the particularagent or agents selected, the particular condition being treated, andthe dosage required for therapeutic efficacy. The methods of thisinvention, generally speaking, may be practiced using any mode ofadministration that is medically acceptable, meaning any mode thatproduces effective levels of an immune response without causingclinically unacceptable adverse effects. Preferred modes ofadministration are discussed herein. For use in therapy, an effectiveamount of the nucleic acid and/or other therapeutic agent can beadministered to a subject by any mode that delivers the agent to thedesired surface, e.g., mucosal, systemic.

Administering the pharmaceutical composition of the present inventionmay be accomplished by any means known to the skilled artisan. Routes ofadministration include but are not limited to oral, parenteral,intravenous, intramuscular, intraperitoneal, intranasal, sublingual,intratracheal, inhalation, subcutaneous, ocular, vaginal, and rectal.For the treatment or prevention of asthma or allergy, such compounds arepreferably inhaled, ingested or administered by systemic routes.Systemic routes include oral and parenteral. Inhaled medications arepreferred in some embodiments because of the direct delivery to thelung, the site of inflammation, primarily in asthmatic patients. Severaltypes of devices are regularly used for administration by inhalation.These types of devices include metered dose inhalers (MDI),breath-actuated MDI, dry powder inhaler (DPI), spacer/holding chambersin combination with MDI, and nebulizers.

The therapeutic agents of the invention may be delivered to a particulartissue, cell type, or to the immune system, or both, with the aid of avector. In its broadest sense, a “vector” is any vehicle capable offacilitating the transfer of the compositions to the target cells. Thevector generally transports the immunostimulatory nucleic acid,antibody, antigen, and/or disorder-specific medicament to the targetcells with reduced degradation relative to the extent of degradationthat would result in the absence of the vector.

In general, the vectors useful in the invention are divided into twoclasses: biological vectors and chemical/physical vectors. Biologicalvectors and chemical/physical vectors are useful in the delivery and/oruptake of therapeutic agents of the invention.

Most biological vectors are used for delivery of nucleic acids and thiswould be most appropriate in the delivery of therapeutic agents that areor that include immunostimulatory nucleic acids.

In addition to the biological vectors discussed herein,chemical/physical vectors may be used to deliver therapeutic agentsincluding immunostimulatory nucleic acids, antibodies, antigens, anddisorder-specific medicaments. As used herein, a “chemical/physicalvector” refers to a natural or synthetic molecule, other than thosederived from bacteriological or viral sources, capable of delivering thenucleic acid and/or other medicament.

A preferred chemical/physical vector of the invention is a colloidaldispersion system. Colloidal dispersion systems include lipid-basedsystems including oil-in-water emulsions, micelles, mixed micelles, andliposomes. A preferred colloidal system of the invention is a liposome.Liposomes are artificial membrane vessels which are useful as a deliveryvector in vivo or in vitro. It has been shown that large unilamellarvesicles (LUVs), which range in size from 0.2-4.0 μm can encapsulatelarge macromolecules. RNA, DNA and intact virions can be encapsulatedwithin the aqueous interior and be delivered to cells in a biologicallyactive form. Fraley et al. (1981) Trends Biochem Sci 6:77.

Liposomes may be targeted to a particular tissue by coupling theliposome to a specific ligand such as a monoclonal antibody, sugar,glycolipid, or protein. Ligands which may be useful for targeting aliposome to an immune cell include, but are not limited to: intact orfragments of molecules which interact with immune cell specificreceptors and molecules, such as antibodies, which interact with thecell surface markers of immune cells. Such ligands may easily beidentified by binding assays well known to those of skill in the art. Instill other embodiments, the liposome may be targeted to the cancer bycoupling it to a one of the immunotherapeutic antibodies discussedearlier. Additionally, the vector may be coupled to a nuclear targetingpeptide, which will direct the vector to the nucleus of the host cell.

Lipid formulations for transfection are commercially available fromQIAGEN, for example, as EFFECTENE™ (a non-liposomal lipid with a specialDNA condensing enhancer) and SUPERFEC™ (a novel acting dendrimerictechnology).

Liposomes are commercially available from Gibco BRL, for example, asLIPOFECTIN™ and LIPOFECTACE™, which are formed of cationic lipids suchas N-[1-(2,3 dioleyloxy)-propyl]-N,N, N-trimethylammonium chloride(DOTMA) and dimethyl dioctadecylammonium bromide (DDAB). Methods formaking liposomes are well known in the art and have been described inmany publications. Liposomes also have been reviewed by Gregoriadis G(1985) Trends Biotechnol 3:235-241.

Certain cationic lipids, including in particular N-[1-(2,3dioleoyloxy)-propyl]-N,N,N-trimethylammonium methyl-sulfate (DOTAP),appear to be especially advantageous when combined with the modifiedoligoribonucleotide analogs of the invention.

In one embodiment, the vehicle is a biocompatible microparticle orimplant that is suitable for implantation or administration to themammalian recipient. Exemplary bioerodible implants that are useful inaccordance with this method are described in PCT Internationalapplication no. PCT/US/03307 (Publication No. WO95/24929, entitled“Polymeric Gene Delivery System”. PCT/US/0307 describes a biocompatible,preferably biodegradable polymeric matrix for containing an exogenousgene under the control of an appropriate promoter. The polymeric matrixcan be used to achieve sustained release of the therapeutic agent in thesubject.

The polymeric matrix preferably is in the form of a microparticle suchas a microsphere (wherein the nucleic acid and/or the other therapeuticagent is dispersed throughout a solid polymeric matrix) or amicrocapsule (wherein the nucleic acid and/or the other therapeuticagent is stored in the core of a polymeric shell). Other forms of thepolymeric matrix for containing the therapeutic agent include films,coatings, gels, implants, and stents. The size and composition of thepolymeric matrix device is selected to result in favorable releasekinetics in the tissue into which the matrix is introduced. The size ofthe polymeric matrix further is selected according to the method ofdelivery which is to be used, typically injection into a tissue oradministration of a suspension by aerosol into the nasal and/orpulmonary areas. Preferably when an aerosol route is used the polymericmatrix and the nucleic acid and/or the other therapeutic agent areencompassed in a surfactant vehicle. The polymeric matrix compositioncan be selected to have both favorable degradation rates and also to beformed of a material which is bioadhesive, to further increase theeffectiveness of transfer when the matrix is administered to a nasaland/or pulmonary surface that has sustained an injury. The matrixcomposition also can be selected not to degrade, but rather, to releaseby diffusion over an extended period of time. In some preferredembodiments, the nucleic acid are administered to the subject via animplant while the other therapeutic agent is administered acutely.Biocompatible microspheres that are suitable for delivery, such as oralor mucosal delivery, are disclosed in Chickering et al. (1996) BiotechBioeng 52:96-101 and Mathiowitz E et al. (1997) Nature 386:410-414 andPCT Pat. Application WO97/03702.

Both non-biodegradable and biodegradable polymeric matrices can be usedto deliver the nucleic acid and/or the other therapeutic agent to thesubject. Biodegradable matrices are preferred. Such polymers may benatural or synthetic polymers. The polymer is selected based on theperiod of time over which release is desired, generally in the order ofa few hours to a year or longer. Typically, release over a periodranging from between a few hours and three to twelve months is mostdesirable, particularly for the nucleic acid agents. The polymeroptionally is in the form of a hydrogel that can absorb up to about 90%of its weight in water and further, optionally is cross-linked withmulti-valent ions or other polymers.

Bioadhesive polymers of particular interest include bioerodiblehydrogels described by H. S. Sawhney, C. P. Pathak and J. A. Hubell inMacromolecules, (1993) 26:581-587, the teachings of which areincorporated herein. These include polyhyaluronic acids, casein,gelatin, glutin, polyanhydrides, polyacrylic acid, alginate, chitosan,poly(methyl methacrylates), poly(ethyl methacrylates),poly(butylmethacrylate), poly(isobutyl methacrylate),poly(hexylmethacrylate), poly(isodecyl methacrylate), poly(laurylmethacrylate), poly(phenyl methacrylate), poly(methyl acrylate),poly(isopropyl acrylate), poly(isobutyl acrylate), and poly(octadecylacrylate).

If the therapeutic agent is a nucleic acid, the use of compaction agentsmay also be desirable. Compaction agents also can be used alone, or incombination with, a biological or chemical/physical vector. A“compaction agent”, as used herein, refers to an agent, such as ahistone, that neutralizes the negative charges on the nucleic acid andthereby permits compaction of the nucleic acid into a fine granule.Compaction of the nucleic acid facilitates the uptake of the nucleicacid by the target cell. The compaction agents can be used alone, i.e.,to deliver a nucleic acid in a form that is more efficiently taken up bythe cell or, more preferably, in combination with one or more of theabove-described vectors.

Other exemplary compositions that can be used to facilitate uptake of anucleic acid include calcium phosphate and other chemical mediators ofintracellular transport, microinjection compositions, electroporationand homologous recombination compositions (e.g., for integrating anucleic acid into a preselected location within the target cellchromosome).

The compounds may be administered alone (e.g., in saline or buffer) orusing any delivery vehicle known in the art. For instance the followingdelivery vehicles have been described: cochleates (Gould-Fogerite etal., 1994, 1996); Emulsomes (Vancott et al., 1998, Lowell et al., 1997);ISCOMs (Mowat et al., 1993, Carlsson et al., 1991, Hu et., 1998, Moreinet al., 1999); liposomes (Childers et al., 1999, Michalek et al., 1989,1992, de Haan 1995a, 1995b); live bacterial vectors (e.g., Salmonella,Escherichia coli, Bacillus Calmette-Guérin, Shigella, Lactobacillus)(Hone et al., 1996, Pouwels et al., 1998, Chatfield et al., 1993, Stoveret al., 1991, Nugent et al., 1998); live viral vectors (e.g., Vaccinia,adenovirus, Herpes Simplex) (Gallichan et al., 1993, 1995, Moss et al.,1996, Nugent et al., 1998, Flexner et al., 1988, Morrow et al., 1999);microspheres (Gupta et al., 1998, Jones et al., 1996, Maloy et al.,1994, Moore et al., 1995, O'Hagan et al., 1994, Eldridge et al., 1989);nucleic acid vaccines (Fynan et al., 1993, Kuklin et al., 1997, Sasakiet al., 1998, Okada et al., 1997, Ishii et al., 1997); polymers (e.g.carboxymethylcellulose, chitosan) (Hamajima et al., 1998, Jabbal-Gill etal., 1998); polymer rings (Wyatt et al., 1998); proteosomes (Vancott etal., 1998, Lowell et al., 1988, 1996, 1997); sodium fluoride (Hashi etal., 1998); transgenic plants (Tacket et al., 1998, Mason et al., 1998,Haq et al., 1995); virosomes (Gluck et al., 1992, Mengiardi et al.,1995, Cryz et al., 1998); and, virus-like particles (Jiang et al., 1999,Leibl et al., 1998).

The formulations of the invention are administered in pharmaceuticallyacceptable solutions, which may routinely contain pharmaceuticallyacceptable concentrations of salt, buffering agents, preservatives,compatible carriers, adjuvants, and optionally other therapeuticingredients.

The term pharmaceutically-acceptable carrier means one or morecompatible solid or liquid filler, diluents or encapsulating substanceswhich are suitable for administration to a human or other vertebrateanimal. The term carrier denotes an organic or inorganic ingredient,natural or synthetic, with which the active ingredient is combined tofacilitate the application. The components of the pharmaceuticalcompositions also are capable of being commingled with the compounds ofthe present invention, and with each other, in a manner such that thereis no interaction which would substantially impair the desiredpharmaceutical efficiency.

For oral administration, the compounds (i.e., nucleic acids, antigens,antibodies, and other therapeutic agents) can be formulated readily bycombining the active compound(s) with pharmaceutically acceptablecarriers well known in the art. Such carriers enable the compounds ofthe invention to be formulated as tablets, pills, dragees, capsules,liquids, gels, syrups, slurries, suspensions and the like, for oralingestion by a subject to be treated. Pharmaceutical preparations fororal use can be obtained as solid excipient, optionally grinding aresulting mixture, and processing the mixture of granules, after addingsuitable auxiliaries, if desired, to obtain tablets or dragee cores.Suitable excipients are, in particular, fillers such as sugars,including lactose, sucrose, mannitol, or sorbitol; cellulosepreparations such as, for example, maize starch, wheat starch, ricestarch, potato starch, gelatin, gum tragacanth, methyl cellulose,hydroxypropylmethyl-cellulose, sodium carboxymethylcellulose, and/orpolyvinylpyrrolidone (PVP). If desired, disintegrating agents may beadded, such as the cross-linked polyvinyl pyrrolidone, agar, or alginicacid or a salt thereof such as sodium alginate. Optionally the oralformulations may also be formulated in saline or buffers forneutralizing internal acid conditions or may be administered without anycarriers.

Dragee cores are provided with suitable coatings. For this purpose,concentrated sugar solutions may be used, which may optionally containgum arabic, talc, polyvinyl pyrrolidone, carbopol gel, polyethyleneglycol, and/or titanium dioxide, lacquer solutions, and suitable organicsolvents or solvent mixtures. Dyestuffs or pigments may be added to thetablets or dragee coatings for identification or to characterizedifferent combinations of active compound doses.

Pharmaceutical preparations which can be used orally include push-fitcapsules made of gelatin, as well as soft, sealed capsules made ofgelatin and a plasticizer, such as glycerol or sorbitol. The push-fitcapsules can contain the active ingredients in admixture with fillersuch as lactose, binders such as starches, and/or lubricants such astalc or magnesium stearate and, optionally, stabilizers. In softcapsules, the active compounds may be dissolved or suspended in suitableliquids, such as fatty oils, liquid paraffin, or liquid polyethyleneglycols. In addition, stabilizers may be added. Microspheres formulatedfor oral administration may also be used. Such microspheres have beenwell defined in the art. All formulations for oral administration shouldbe in dosages suitable for such administration.

For buccal administration, the compositions may take the form of tabletsor lozenges formulated in conventional manner.

For administration by inhalation, the compounds for use according to thepresent invention may be conveniently delivered in the form of anaerosol spray presentation from pressurized packs or a nebulizer, withthe use of a suitable propellant, e.g., dichlorodifluoromethane,trichlorofluoromethane, dichlorotetrafluoroethane, carbon dioxide orother suitable gas. In the case of a pressurized aerosol the dosage unitmay be determined by providing a valve to deliver a metered amount.Capsules and cartridges of e.g. gelatin for use in an inhaler orinsufflator may be formulated containing a powder mix of the compoundand a suitable powder base such as lactose or starch.

The compounds, when it is desirable to deliver them systemically, may beformulated for parenteral administration by injection, e.g., by bolusinjection or continuous infusion. Formulations for injection may bepresented in unit dosage form, e.g., in ampoules or in multi-dosecontainers, with an added preservative. The compositions may take suchforms as suspensions, solutions or emulsions in oily or aqueousvehicles, and may contain formulatory agents such as suspending,stabilizing and/or dispersing agents.

Pharmaceutical formulations for parenteral administration includeaqueous solutions of the active compounds in water-soluble form.Additionally, suspensions of the active compounds may be prepared asappropriate oily injection suspensions. Suitable lipophilic solvents orvehicles include fatty oils such as sesame oil, or synthetic fatty acidesters, such as ethyl oleate or triglycerides, or liposomes. Aqueousinjection suspensions may contain substances which increase theviscosity of the suspension, such as sodium carboxymethyl cellulose,sorbitol, or dextran. Optionally, the suspension may also containsuitable stabilizers or agents which increase the solubility of thecompounds to allow for the preparation of highly concentrated solutions.

Alternatively, the active compounds may be in powder form forconstitution with a suitable vehicle, e.g., sterile pyrogen-free water,before use.

The compounds may also be formulated in rectal or vaginal compositionssuch as suppositories or retention enemas, e.g., containing conventionalsuppository bases such as cocoa butter or other glycerides.

In addition to the formulations described previously, the compounds mayalso be formulated as a depot preparation. Such long-acting formulationsmay be formulated with suitable polymeric or hydrophobic materials (forexample as an emulsion in an acceptable oil) or ion exchange resins, oras sparingly soluble derivatives, for example, as a sparingly solublesalt.

The pharmaceutical compositions also may comprise suitable solid or gelphase carriers or excipients. Examples of such carriers or excipientsinclude but are not limited to calcium carbonate, calcium phosphate,various sugars, starches, cellulose derivatives, gelatin, and polymerssuch as polyethylene glycols.

Suitable liquid or solid pharmaceutical preparation forms are, forexample, aqueous or saline solutions for inhalation, microencapsulated,encochleated, coated onto microscopic gold particles, contained inliposomes, nebulized, aerosols, pellets for implantation into the skin,or dried onto a sharp object to be scratched into the skin. Thepharmaceutical compositions also include granules, powders, tablets,coated tablets, (micro)capsules, suppositories, syrups, emulsions,suspensions, creams, drops or preparations with protracted release ofactive compounds, in whose preparation excipients and additives and/orauxiliaries such as disintegrants, binders, coating agents, swellingagents, lubricants, flavorings, sweeteners or solubilizers arecustomarily used as described above. The pharmaceutical compositions aresuitable for use in a variety of drug delivery systems. For a briefreview of methods for drug delivery, see Langer R (1990) Science249:1527-1533, which is incorporated herein by reference.

The nucleic acids and optionally other therapeutics and/or antigens maybe administered per se (neat) or in the form of a pharmaceuticallyacceptable salt. When used in medicine the salts should bepharmaceutically acceptable, but non-pharmaceutically acceptable saltsmay conveniently be used to prepare pharmaceutically acceptable saltsthereof. Such salts include, but are not limited to, those prepared fromthe following acids: hydrochloric, hydrobromic, sulphuric, nitric,phosphoric, maleic, acetic, salicylic, p-toluene sulphonic, tartaric,citric, methane sulphonic, formic, malonic, succinic,naphthalene-2-sulphonic, and benzene sulphonic. Also, such salts can beprepared as alkaline metal or alkaline earth salts, such as sodium,potassium or calcium salts of the carboxylic acid group.

Suitable buffering agents include: acetic acid and a salt (1-2% w/v);citric acid and a salt (1-3% w/v); boric acid and a salt (0.5-2.5% w/v);and phosphoric acid and a salt (0.8-2% w/v). Suitable preservativesinclude benzalkonium chloride (0.003-0.03% w/v); chlorobutanol (0.3-0.9%w/v); parabens (0.01-0.25% w/v) and thimerosal (0.004-0.02% w/v).

The compositions may conveniently be presented in unit dosage form andmay be prepared by any of the methods well known in the art of pharmacy.All methods include the step of bringing the compounds into associationwith a carrier which constitutes one or more accessory ingredients. Ingeneral, the compositions are prepared by uniformly and intimatelybringing the compounds into association with a liquid carrier, a finelydivided solid carrier, or both, and then, if necessary, shaping theproduct. Liquid dose units are vials or ampoules. Solid dose units aretablets, capsules and suppositories.

Other delivery systems can include time-release, delayed release orsustained release delivery systems. Such systems can avoid repeatedadministrations of the compounds, increasing convenience to the subjectand the physician. Many types of release delivery systems are availableand known to those of ordinary skill in the art. They include polymerbase systems such as poly(lactide-glycolide), copolyoxalates,polycaprolactones, polyesteramides, polyorthoesters, polyhydroxybutyricacid, and polyanhydrides. Microcapsules of the foregoing polymerscontaining drugs are described in, for example, U.S. Pat. No. 5,075,109.Delivery systems also include non-polymer systems that are: lipidsincluding sterols such as cholesterol, cholesterol esters and fattyacids or neutral fats such as mono-, di-, and tri-glycerides; hydrogelrelease systems; silastic systems; peptide-based systems; wax coatings;compressed tablets using conventional binders and excipients; partiallyfused implants; and the like. Specific examples include, but are notlimited to: (a) erosional systems in which an agent of the invention iscontained in a form within a matrix such as those described in U.S. Pat.Nos. 4,452,775, 4,675,189, and 5,736,152, and (b) diffusional systems inwhich an active component permeates at a controlled rate from a polymersuch as described in U.S. Pat. Nos. 3,854,480, 5,133,974 and 5,407,686.In addition, pump-based hardware delivery systems can be used, some ofwhich are adapted for implantation.

The present invention is further illustrated by the following Examples,which in no way should be construed as further limiting.

EXAMPLES Example 1 Responsiveness of Human PBMC to N-U-R₁-R₂,-ContainingOligoribonucleotides

Methods: Luminex Technology

Luminex color-codes tiny beads, called microspheres, into 100 distinctsets. Each bead set can be coated with a reagent specific to aparticular bioassay, allowing the capture and detection of specificanalytes from a sample. Within the Luminex compact analyzer, lasersexcite the internal dyes that identify each microsphere particle, andalso any reporter dye captured during the assay. Many readings are madeon each bead set, further validating the results. In this way, Luminextechnology allows multiplexing of up to 100 unique assays within asingle sample, both rapidly and precisely.

Human peripheral blood mononuclear cells (PBMCs) were isolated fromhealthy donors, plated, and stimulated in vitro with various test andcontrol immunostimulatory agents for 16 hours. After 16 hours, thesupernatants were collected and then analyzed by ELISA assay.N-U-R₁-R₂,-Containing Oligoribonucleotides were tested complexed toDOTAP and with full titration curves (7 concentrations), starting from 2μM ORN complexed to 25 μg/ml DOTAP and with 1/3 dilution steps. Alsoincluded were certain negative controls, including medium alone andDOTAP (25 μg/ml culture well; “Liposomes”) alone. The controlimmunostimulatory agents included the imidazoquinoline R-848 (2 μM with1/3 dilution steps and 7 concentrations) the reported ligand for TLR7,ORN having TLR8 motifs such as AU and AUU sequences (SEQ ID NO:13-SEQ IDNO:15) ORN having TLR7/8 motifs such as CU, GU and GUU sequences (SEQ IDNO:19-SEQ ID NO:23). The results are shown in FIGS. 1 and 3.

A similar assay testing different ORN sequences was performed usingisolated pDC, monocytes and mDC stimulation. Cells were stimulated with0.5 μM ORN complexed to 10 μg/ml DOTAP, 0.5 μM CpG ODN or DOTAP or mediaalone. After 16 h the supernatants were harvested and IFN-alpha,TNF-alpha and IL-12p40 levels were measured by ELISA. The results areshown in FIG. 2.

FIG. 1 shows a clear difference between TNF-alpha and IFN-alphaproduction upon PBMC stimulation for SEQ ID NO:12 containing an AUsequence and SEQ ID NO:21 containing a GU sequence. Further sequenceanalysis revealed that a CUA repetition (SEQ ID NO:24) is an additionalTNF-alpha inducing ORN with no IFN-alpha production. Shorter ORNcontaining AU and GU repetitions (SEQ ID NO:29-SEQ ID NO:34) showedsimilar results compared to longer ones (SEQ ID NO:12-SEQ ID NO:23) butwith a drop in efficacy and potency.

FIGS. 2 and 6 show analysis of AU-ORN (SEQ ID NO:13) and GU-ORN (SEQ IDNO:21) on isolated monocytes, pDCs and mDCs reflecting strongly reducedIFN-alpha production for AU-ORN (SEQ ID NO:13) and clear TNF-alpha andIL-12p40 production for both ORN. IFN-alpha production upon ORNstimulation from pDC appears to be TLR7 mediated while TNF-alpha andIL-12p40 production from isolated monocytes and mDC appears to be TLR8mediated.

Luminex results reflected comparable results to ELISA data and provedthat the major difference between GU-ORN and AU-ORN is due to IFN-alphaproduction and IFN-alpha related genes/cytokines (FIGS. 3 and 8 a). Inaddition, further Luminex data showed that in contrast to IFN-alpha andIFN-alpha related genes/cytokines the other cytokines/chemokines areunaffected (FIGS. 7 and 8 a-d) with one outlier IL-6 from CD123-CD14−cells. This IL-6 production might be due to TLR7 mediated B-cellactivation.

Example 2 Comparison of IFN-Alpha and TNF-Alpha Max Activities ofOligoribonucleotides

Human PBMC were stimulated with ORN complexed to DOTAP. After 16 hourssupernatants were harvested and TNF-alpha and IFN-alpha levels weremeasured. Mean/Max activities at 0.6 μM of 3-6 blood donors and twoindividual experiments were determined. The results are shown in FIG. 4.These data clearly differentiate between the TLR8 and TLR7/8 motifs: ORNwith the motif N-U-R₁-R₂ showed IFN-alpha production under 300 pg/mlwhile TLR7/8 ORN showed higher IFN-alpha production upon PBMCstimulation (FIG. 4 a). TLR8 and TLR7/8 ORN are divided by a red line.In contrast, measurements of TNF-alpha levels indicated that both ORNwith the TLR8 and ORN with the TLR7/8 motif stimulate TNF-alphaproduction.

Example 3 Comparison of IFN-Alpha Max Activity to IFN-Alpha EC50 ofOligoribonucleotides

Human PBMC were stimulated with ORN complexed to DOTAP. After 16 hourssupernatants were harvested and IFN-alpha levels were measured. Mean/Maxactivities at 0.6 μM and EC50 of full titration curves (range: 2 μM to0.9 nM) of 3-6 blood donors and two individual experiments weredetermined. The results are shown in FIG. 5. EC50 and Max activitiesshowed comparable results concerning the TLR8 and TLR7/8 motifs. LowEC50/high Max activity represents TLR7/8 ORN (FIG. 5 a) whereas highEC50 and low Max activity represents TLR8 ORN (FIG. 5 b).

The ORN sequences listed in Table 1 were tested for IFN-alpha andTNF-alpha production upon human PBMC stimulation. Human PBMC werestimulated for 16 h with the indicated ORN, and supernatants wereharvested and cytokine production measured by ELISA. Table 2 summarizesthe min/max activity and EC50 of ORN for IFN-alpha and TNF-alphaproduction. TABLE 1 IFN- TNF- alpha alpha SEQ ID NO:1 G*U*A*G*G*C*A*C− + SEQ ID NO:2 U*U*A*G*G*C*A*C − + SEQ ID NO:3 C*U*A*G*G*C*A*C − + SEQID NO:4 A*U*A*G*G*C*A*C − + SEQ ID NO:7 dN*dN*dN*dN*dN*N*A*U*A* − +U*N*N*dN*dN*dN*dN*dN*dN SEQ ID NO:9 dN*dN*dN*dN*dN*A*U*A*U* − +A*U*A*U*dN*dN*dN*dN*dN* dN SEQ ID NO:11 G*C*C*A*C*C*G*A*G*C*C*G* − +A*A*U*A*U*A*C*C SEQ ID NO:12 A*U*A*U*A*U*A*U*A*U*A*U* − +A*U*A*U*A*U*A*U SEQ ID NO:13 U*U*A*U*U*A*U*U*A*U*U*A* − +U*U*A*U*U*A*U*U SEQ ID NO:14 U*U*U*A*U*U*U*A*U*U*U*A* + +U*U*U*A*U*U*U*A SEQ ID NO:15 U*U*U*U*A*U*U*U*U*A*U*U* + +U*U*A*U*U*U*U*A SEQ ID NO:16 A*A*U*A*A*U*A*A*U*A*A*U* − +A*A*U*A*A*U*A*A SEQ ID NO:17 A*A*A*U*A*A*A*U*A*A*A*U* − +A*A*A*U*A*A*A*U SEQ ID NO:18 A*A*A*A*U*A*A*A*A*U*A*A* − +A*A*U*A*A*A*A*U SEQ ID NO:19 C*U*C*U*C*U*C*U*C*U*C*U* + +C*U*C*U*C*U*C*U SEQ ID NO:20 G*U*G*U*G*U*G*U*G*U*G*U* + +G*U*G*U*G*U*G*U SEQ ID NO:21 U*U*G*U*U*G*U*U*G*U*U*G* + +U*U*G*U*U*G*U*U SEQ ID NO:22 U*U*U*G*U*U*U*G*U*U*U*G* + +U*U*U*G*U*U*U*G SEQ ID NO:23 U*U*U*U*G*U*U*U*U*G*U*U* + +U*U*G*U*U*U*U*G SEQ ID NO:24 C*U*A*C*U*A*C*U*A*C*U*A* − +C*U*A*C*U*A*C*U SEQ ID NO:25 G*U*A*G*U*A*G*U*A*G*U*A* + +G*U*A*G*U*A*G*U SEQ ID NO:26 G*U*C*G*U*C*G*U*C*G*U*C* + +G*U*C*G*U*C*G*U SEQ ID NO:27 I*U*A*I*U*A*I*U*A*I*U*A* + +I*U*A*I*U*A*I*U SEQ ID NO:28 U*U*I*U*U*I*U*U*I*U*U*I* + +U*U*I*U*U*I*U*U SEQ ID NO:29 U*U*G*U*U*G*U + + SEQ ID NO:30U*U*A*U*U*A*U − + SEQ ID NO:31 U*G*U*G*U*G*U + + SEQ ID NO:32U*C*U*C*U*C*U + + SEQ ID NO:33 U*A*U*A*U*A*U − + SEQ ID NO:34G*U*A*G*U*A*G + ++: cytokine production−: no cytokine production.

TABLE 2 IFN-alpha TNF-alpha max max activity activity IFN-alphaTNF-alpha ORN [pg/ml] [pg/ml] EC50 [μM] EC50 [μM] SEQ ID NO:49C*C*G*A*G*C*C*G*C*U*U*A*A 3367 710.4 18039 5982 0.375 0 0.35 0 *C*C*CSEQ ID NO:53 C*C*G*A*G*C*C*G*C*U*U*A*C 3091 1028 14623 2088 0.244 00.952 0 *C*C*C SEQ ID NO:51 C*C*G*A*G*C*C*G*C*U*A*U*U 2615 893.9 233253378 0.582 0 0.125 0 *C*C*C SEQ ID NO:50 C*C*G*A*G*C*C*G*C*A*A*U*U 2614599.2 11141 5133 0.562 0 0.564 0 *C*C*C SEQ ID NO:77C*C*G*A*G*C*C*G*A*G*U*U*C 2519 336.9 21820 8316 0.151 0.15 0.257 0.095*A*C*C SEQ ID NO:52 C*C*G*A*G*C*C*G*C*A*A*U*U 2263 744.8 11920 56540.508 0 0.895 0 *C*C*C SEQ ID NO:67 C*C*G*A*G*C*C*G*A*G*U*U*C 2094 040729 0 0.081 0 0.079 0 *A*C*C SEQ ID NO:62 C*C*G*A*G*C*C*G*A*T*U*G*U1945 503.8 37334 4597 0.276 0.029 0.343 0.004 *A*C*C SEQ ID NO:72C*C*G*A*G*C*C*G*A*U*U*U*T 1896 476.1 38811 11366 0.075 0.019 0.146 0.037*A*C*C SEQ ID NO:68 C*C*G*A*G*C*C*G*A*T*U*U*C 1821 0 29647 0 0.018 00.217 0 *A*C*C SEQ ID NO:58 C*C*G*A*G*C*C*G*A*G*U*U*U 1760 423.3 366279350 0.063 0.047 0.203 0.08 *A*C*C SEQ ID NO:59C*C*G*A*G*C*C*G*A*T*U*U*U 1714 473.8 26762 691.6 0.074 0.036 0.224 0.106*A*C*C SEQ ID NO:70 C*C*G*A*G*C*C*G*A*U*T*U*T 1702 554.3 44904 109720.132 0.035 0.15 0.029 *A*C*C SEQ ID NO:71 C*C*G*A*G*C*C*G*A*U*U*U*C1626 629.7 45164 13344 0.051 0.023 0.16 0.011 *A*C*C SEQ ID NO:66C*C*G*A*G*C*C*G*A*U*G*U*U 1616 188.4 43098 3722 0.558 0.326 0.051 0.033*A*C*C SEQ ID NO:78 C*C*G*A*G*C*C*G*A*T*U*U*C 1609 805.1 20126 43420.006 0.002 0.241 0.139 *A*C*C SEQ ID NO:57 C*C*G*A*G*C*C*G*A*C*U*U*U1499 54.8 33624 1507 0.077 0.034 0.213 0.072 *A*C*C SEQ ID NO:60C*C*G*A*G*C*C*G*A*A*U*U*U 1463 192.9 36562 2374 0.109 0.036 0.187 0.06*A*C*C SEQ ID NO:64 C*C*G*A*G*C*C*G*A*U*C*U*U 1421 0 30712 0 0.577 00.289 0 *A*C*C SEQ ID NO:73 C*C*G*A*G*C*C*G*A*U*U*U*A 1395 367.9 3161910958 0.055 0.013 0.163 0.024 *A*C*C SEQ ID NO:54C*C*G*A*G*C*C*G*C*A*U*U*C 1233 772.4 12595 5272 0.78 0 0.339 0 *C*C*CSEQ ID NO:80 C*C*G*A*G*C*C*G*A*A*U*U*C 1225 486.6 28108 3911 0.033 0.020.217 0.022 *A*C*C SEQ ID NO:79 C*C*G*A*G*C*C*G*A*T*U*U*C 1152 402.717728 415.8 0.035 0.02 0.334 0.138 *A*C*C SEQ ID NO:69C*C*G*A*G*C*C*G*A*U*C*U*C 1031 584.8 26915 3185 0.619 0.582 0.313 0.174*A*C*C SEQ ID NO:75 C*C*G*A*G*C*C*G*A*U*U*C*T 929.9 408.7 27576 47121.297 0.433 0.129 0.071 *A*C*C SEQ ID NO:86 C*C*G*A*G*C*C*G*A*A*G*G*U856.5 212.6 4178 2818 0.767 0 0.85 0 *C*C*C SEQ ID NO:81C*C*G*A*G*C*C*G*A*G*C*U*C 842.9 0 14519 3965 0.667 0.083 0.802 0.093*A*C*C SEQ ID NO:74 C*C*G*A*G*C*C*G*A*U*U*G*C 609.1 141.6 30958 132750.419 0.408 0.329 0.067 *A*C*C SEQ ID NO:61 C*C*G*A*G*C*C*G*A*C*U*G*U587.7 223.7 42180 2040 0.736 0.009 0.141 0.077 *A*C*C SEQ ID NO:48C*C*G*A*G*C*C*G*C*A*U*U*A 543.4 457.8 9988 3681 0.75 0 0.801 0 *C*C*CSEQ ID NO:76 C*C*G*A*G*C*C*G*A*U*U*G*A 448.6 323.9 26371 7157 1.5430.457 0.109 0.017 *A*C*C SEQ ID NO:42 C*C*G*A*G*C*C*G*A*A*U*A*C 392.4277.9 17418 3300 1.5 0 0.395 0 *C*C*C SEQ ID NO:39C*C*G*A*G*C*C*A*U*A*U*A*U 356.7 262.3 19253 4261 1.5 0 0.324 0 *A*U*CSEQ ID NO:65 C*C*G*A*G*C*C*G*A*U*A*U*U 335.2 63.87 39377 3971 1.131 0.030.077 0.002 *A*C*C SEQ ID NO:44 C*C*G*A*G*C*C*G*A*A*U*C*C 305.6 163.319473 7758 1.5 0 0.321 0 *C*C*C SEQ ID NO:47 C*C*G*A*G*C*C*G*C*C*U*A*C271.9 204 14265 4080 1.5 0 0.566 0 *C*C*C SEQ ID NO:38C*C*G*A*G*C*C*A*U*A*U*A*U 245 148.3 14064 3564 1.5 0 0.89 0 *C*C*C SEQID NO:37 C*C*G*A*G*C*C*G*C*U*A*U*A 240.5 161.2 22800 6376 1.5 0 0.75 0*C*C*C SEQ ID NO:40 C*C*G*A*G*C*C*G*A*A*U*A*A 235.3 124.3 18083 4101 1.50 0.352 0 *C*C*C SEQ ID NO:55 C*C*G*A*G*C*C*G*C*U*A*U*C 224.4 772.415154 5272 2 0 0.337 0 *C*C*C SEQ ID NO:82 C*C*G*A*G*C*C*G*A*A*G*G*U 20428.62 12595 4373 2 0 0.219 0 *A*C*C SEQ ID NO:85C*C*G*A*G*C*C*G*A*A*G*A*U 193.7 37.15 17146 7964 2 0 0.215 0 *A*C*C SEQID NO:63 C*C*G*A*G*C*C*G*A*A*U*G*U 177.3 6.443 34219 5563 1.836 0.0940.309 0.151 *A*C*C SEQ ID NO:43 C*C*G*A*G*C*C*G*C*C*U*A*A 144.3 74.5110261 2883 2 0 0.954 0 *C*C*C SEQ ID NO:36 C*C*G*A*G*C*C*G*C*A*U*A*U110.4 32.54 18063 6409 1.5 0 0.85 0 *C*C*C SEQ ID NO:87C*C*G*A*G*C*C*G*A*A*G*C*U 100.5 73.84 12979 6676 2 0 0.346 0 *A*C*C SEQID NO:45 C*C*G*A*G*C*C*G*C*A*U*A*C 98.44 42.34 10491 4195 1.7 0 0.754 0*C*C*C SEQ ID NO:41 C*C*G*A*G*C*C*G*C*A*U*A*A 97.97 42.23 10756 3679 2 00.897 0 *C*C*C SEQ ID NO:83 C*C*G*A*G*C*C*G*A*A*G*G*U 96.22 2.398 122076121 2 0 0.215 0 *G*C*C SEQ ID NO:46 C*C*G*A*G*C*C*G*C*A*U*C*C 74.7632.92 7096 1767 2 0 0.765 0 *C*C*C SEQ ID NO:88C*C*G*A*G*C*C*G*A*A*G*C*U 73.19 34.21 11996 6696 2 0 2 0 *G*C*C SEQ IDNO:35 C*C*G*A*G*C*C*G*C*C*G*C*C 70.6 11.78 2854 1505 2 0 2 0 *C*C*C SEQID NO:84 C*C*G*A*G*C*C*G*A*A*G*C*U 67.76 15.71 8545 3592 2 0 0.377 0*C*C*C SEQ ID NO:56 C*C*G*A*G*C*C*G*A*A*G*G*C 59.84 8.006 4430 1124 2 02 0 *A*C*C

Example 4 Synthetic ORN Differentiate Between IFN-Alpha and TNF-AlphaRelease Upon Human PBMC Stimulation

CD123+ purified pDC (FIGS. 10 a and 10 b) or isolated monocytes (FIG. 10c) were incubated with 1 μM ORN complexed to 25 μg/ml DOTAP or DOTAPalone (FIG. 10 a) or indicated amounts of ORN complexed to DOTAP orDOTAP alone (FIGS. 10 b-10 c). After 16 h cells were harvested andstained with CD123, CD11c and HLA-DR antibodies (FIGS. 10 a and 10 b) orCD14 and CD19 (FIG. 10 c). FACS analysis for CD86 shows that AU-rich ORN(SEQ ID NO:13) and GU-rich ORN (SEQ ID NO:21) show differences in CD86surface marker expression upon pDC stimulation (FIG. 10 a). Stimulationwith AU-rich ORN SEQ ID NO:13 resulted in very little CD86 activation,whereas stimulation with GU-rich ORN SEQ ID NO:21 resulted insignificant CD86 activation. This activation was determined to bedose-dependent (FIG. 10 b). AU-rich ORN (SEQ ID NO:13) and GU-rich ORN(SEQ ID NO:21) showed no difference in CD80 surface marker expressionupon human PBMC (data not shown) and CD14-positive cell stimulation(FIG. 10 c).

Example 5 A U-Rich ORN (SEQ ID NO:13) and GU-Rich ORN (SEQ ID NO:21)Stimulate Specific Human TLR8 Signaling in a Dose Dependent Manner

Unresponsive HEK-293 cells were stably transfected with human TLR3 orTLR8 expression plasmid and NFκB-luciferase reporter gene construct.Cells were incubated with the indicated ORN sequences (10 μM complexedto 50 μg/ml DOTAP) or control stimuli (10 μM R-848, 50 μg/ml polyIC,3.3CM ODN 10103 or 50 μg/ml DOTAP) for 16 hours. NFκB-activation wasmeasured by assaying luciferase activity. Results are given as foldinduction above background (medium). One representative experiment of 6independent repetitions is presented (FIG. 9 a).

Stable-transfected HEK-293 cells expressing human TLR8 were stimulatedwith indicated concentrations of ORN complexed to DOTAP (50 μg/ml->1/3dilution) or DOTAP alone (50 μg/ml->1/3 dilution) for 16 hours. NFκBactivation was measured by assaying luciferase activity. Results aregiven as fold induction above background (medium). One representativeexperiment of 3 independent repetitions is presented (FIG. 9 b).

Unresponsive HEK-293 cells were stably transfected with human TLR8expression plasmid and NFκB-luciferase reporter gene construct. Cellswere incubated with the indicated ORN sequences (15 μM complexed to 75μg/ml DOTAP) or control stimuli (15 μM R-848 or 75 μg/ml DOTAP) and withmedia (left), 200 nM Bafilomycin (Baf., middle) or 1 mM Chloroquine (CQ,right) for 16 h. NFκB-activation was measured by assaying luciferaseactivity. Results are given as fold induction above background (medium).One representative experiment of 4 independent repetitions is presented(FIG. 9 c).

RPMI 8226 cells were pre-incubated with 1000 U/ml Intron A for 3 hours,washed twice with media and then stimulated for 16 hours with theindicated concentrations of ORN complexed to DOTAP (50 μg/ml->1/3dilution). Cytokine release of IP-10 was measured by ELISA. Results aregiven as pg/ml. One representative experiment of 3 independentrepetitions is presented (FIG. 9 d).

These data demonstrate the specificity of SEQ ID NO:13 and SEQ ID NO:21for TLR8

The assay was repeated with a TLR8 ORN (SEQ ID NO:13), a TLR 7/8 ORN(SEQ ID NO:21) and a control ORN (SEQ ID NO:5) (Table 3) at both a highdose (H.D., 10 μg/ml) and a low dose (L.D., 2.5 μg/ml). Only SEQ IDNO:21 treatment resulted in significant production of IL-12 andTNF-alpha (FIGS. 11 a and 11 b, respectively). All ORN stimulatedproduction of IFN-γ (FIG. 11 c). SEQ ID NO ORN SEQ ID NO:5C*C*G*U*C*U*G*U*U*G*U*G*U*G*A*C*U*C SEQ ID NO:13U*U*A*U*U*A*U*U*A*U*U*A*U*U*A*U*U*A*U *U SEQ ID NO:21U*U*G*U*U*G*U*U*G*U*U*G*U*U*G*U*U*G*U *U

Example 6 Mouse Macrophages do not Respond to AU-Rich ORN (SEQ ID NO:13)In Vitro or In Vivo

Raw264.7 cells (FIG. 12 a), J774 cells (FIG. 12 b) and purified CD11c+cells (Milteny, magnetic bead labeling) were isolated from sv129 micesplenocytes (FIGS. 12 c-12 e) and were stimulated with indicatedconcentrations of ORN complexed to DOTAP (50 μg/ml and diluted withORN), R-848 or DOTAP alone (50 μg/ml). After 16 hours (FIGS. 12 a and 12b) or 20 hours (FIGS. 12 c-12 e) supernatants were harvested and usedfor TNF-alpha (FIGS. 12 a and 12 b), IL-12p40 (FIG. 12 c), IFN-alpha(FIG. 12 d) and IP-10 (FIG. 12 e) ELISA. Data represent one individualfrom at least three experiments (FIGS. 12 a and 12 b) and mean of 3 mice(FIGS. 12 c-12 e). To measure the ability of AU-rich ORN to stimulatemouse cells in vivo, sv129 mice (n=5/group) were injected with theindicated amounts of ORN formulated with DOTAP (60, 20 or 6 μg/ml), andbled after 3 hours. IL-12p40 (FIG. 12 f), IFN-alpha (FIG. 12 g) andIP-10 (FIG. 12 h) production was measured within whole blood by ELISA.

Example 7 Purified Rat Splenocytes do not Respond to AU-Rich ORN SEQ IDNO:13

Splenocytes from 3 Sprague-Dawley rats were pooled and stimulated withindicated concentrations of SEQ ID NO:21, SEQ ID NO:13 (both complexedto 62.5 μg/ml DOTAP with 1/5 dilution), R-848 or DOTAP alone (62.5μg/ml->1/5 dilution). Supernatants were harvested after 20 hours andTNF-alpha levels were measured by ELISA. As shown in FIG. 13,stimulation with GU-rich ORN SEQ ID NO:21 resulted in TNF-alphaproduction, whereas stimulation with AU-rich ORN SEQ ID NO:13 resultedin no TNF-alpha production.

Example 8

Failure of Rodent Cells to Respond to Au-Rich ORN SEQ ID NO:13 mayResult from TLR8 Polymorphism Among Species

Stimulation of human and bovine cells with AU-rich ORN resulted incytokine production, whereas stimulation of mouse and rat cells did not.A TLR8 sequence alignment and analysis was performed. Protein sequencecomparison of TLR8 among different vertebrates (human, monkey,chimpanzee, dog, cow, pig, mouse and rat) showed strong differenceswithin leucine rich repeat (LRR) 3 of domain 1. While human, chimpanzeeand monkey are highly conserved, rat, mouse and pig demonstrateddeletions of 4 AA at position 106 (mouse), 103 (rat) or 102 (pig), andcow demonstrated an insertion of 2AA (105-106) compared to humans.Interestingly, pig and cattle revealed another deletion of 2 AA withinthe same region (position 97). It is possible that the deletion in theleucine rich repeat region of domain 1 may interfere with AU-rich ORNbinding.

EQUIVALENTS

The foregoing written specification is considered to be sufficient toenable one skilled in the art to practice the invention. The presentinvention is not to be limited in scope by examples provided, since theexamples are intended as a single illustration of one aspect of theinvention and other functionally equivalent embodiments are within thescope of the invention. Various modifications of the invention inaddition to those shown and described herein will become apparent tothose skilled in the art from the foregoing description and fall withinthe scope of the appended claims. The advantages of the invention arenot necessarily encompassed by each embodiment of the invention.

All references, patents and patent publications that are recited in thisapplication are incorporated in their entirety herein by reference.

1. A method for stimulating production of a pro-inflammatory cytokine,comprising: contacting a TLR8 expressing cell in vitro with an RNAoligonucleotide (ORN) comprising: N-U-R₁-R₂, wherein N is aribonucleotide and N does not include a U, U is Uracil or a derivativethereof, and R is a ribonucleotide wherein at least one of R₁ and R₂ isAdenosine (A) or Cytosine or derivatives thereof and wherein R is not Uunless N-U-R₁-R₂ includes at least two A, wherein the ORN is notACCCAUCUAUUAUAUAACUC (SEQ ID NO:89) and does not include a TLR7/8 motifand wherein the ORN is 4-100 in length, in an effective amount tostimulate pro-inflammatory cytokine production and wherein IFN-αproduction in response to the ORN is not induced significantly relativeto background.
 2. A method for stimulating production of apro-inflammatory cytokine, comprising: contacting a TLR₈ expressing cellin vitro with an RNA oligonucleotide (ORN) comprising: N-U-R₁-R₂,wherein N is a ribonucleotide and N does not include a U, U is Uracil ora derivative thereof, and R is a ribonucleotide wherein at least one ofR₁ and R₂ is Adenosine (A) or Cytosine or derivatives thereof andwherein R is not U unless N-U-R₁-R₂ includes at least two A, wherein theORN does not include a TLR7/8 motif and is not complexed toN-[1-(2,3-Dioleoyloxy)propyl]-N,N,Ntrimethylammoniummethyl-sulfate(DOTAP) and wherein the ORN is 4-100 in length, in an effective amountto stimulate pro-inflammatory cytokine production and wherein IFN-αproduction in response to the ORN is not induced significantly relativeto background.
 3. The method of claim 1, wherein IFN-α production inresponse to the ORN is less than 300 pg/ml.
 4. The method of claim 1,wherein the ORN is complexed toN-[1-(2,3-Dioleoyloxy)propyl]-N,N,Ntrimethylammoniummethyl-sulfate(DOTAP) or a polycationic peptide.
 5. The method of claim 1, wherein Nis Adenosine or Cytosine (C) or derivatives thereof.
 6. The method ofclaim 1, wherein N is an Adenosine or Cytosine.
 7. The method of claim1, wherein U is Uracil.
 8. The method of claim 1, wherein the ORNincludes at least one AU.
 9. The method of claim 1, wherein the ORNincludes at least one CU.
 10. The method of claim 1, wherein the TLR8expressing cell is a monocyte or a monocyte-derived dendritic cell.11-18. (canceled)
 19. An RNA oligonucleotide (ORN) comprising:N-U-R₁-R₂, wherein N is a ribonucleotide and N does not include a U, Uis Uracil or a derivative thereof, and R is a ribonucleotide wherein atleast one of R₁ and R₂ is Adenosine (A) or Cytosine or derivativesthereof and wherein R is not U unless N-U-R₁-R₂ includes at least two A,wherein the ORN is not ACCCAUCUAUUAUAUAACUC (SEQ ID NO:89) and does notinclude a TLR7/8 motif and wherein the ORN is 4-100 in length andincludes at least one backbone modification.
 20. The ORN of claim 19,further comprising a pharmaceutically acceptable carrier.
 21. The ORN ofclaim 19, wherein the ORN is complexed toN-[1-(2,3-Dioleoyloxy)propyl]-N,N,Ntrimethylammoniummethyl-sulfate(DOTAP).
 22. The ORN of claim 19, wherein the ORN is single stranded.23. An RNA oligonucleotide (ORN) comprising: N-U-R₁-R₂, wherein N is aribonucleotide and N does not include a U, U is Uracil or a derivativethereof, and R is a ribonucleotide wherein at least one of R₁ and R₂ isAdenosine (A) or Cytosine or derivatives thereof and wherein R is not Uunless N-U-R₁-R₂ includes at least two A, wherein the ORN does notinclude a TLR7/8 motif and is not complexed toN-[1-(2,3-Dioleoyloxy)propyl]-N,N,Ntrimethylammoniummethyl-sulfate(DOTAP) and wherein the ORN is 4-100 in length and includes at least onebackbone modification and is formulated in a pharmaceutically acceptablecarrier.
 24. The ORN of claim 19, wherein N is an Adenosine or Cytosine(C) or derivatives thereof.
 25. The ORN of claim 19, wherein N is anAdenosine or Cytosine.
 26. The ORN of claim 19, wherein U is Uracil. 27.The ORN of claim 19, wherein the ORN includes at least one AU.
 28. TheORN of claim 19, wherein the ORN includes at least one CU.
 29. The ORNof claim 19, wherein N-U-R₁-R₂ includes at least 3 As.
 30. The ORN ofclaim 19, wherein N-U-R₁-R₂ includes at least 2 Cs.
 31. The ORN of claim19, wherein N-U-R₁-R₂ includes at least one G or C.
 32. The ORN of claim19, wherein the ORN is single stranded.
 33. The ORN of claim 19, whereinthe ORN is one of the following: U*U*A*G*G*A*C, (SEQ ID NO:2)A*U*A*G*G*C*A*C, (SEQ ID NO:4) G*C*C*A*C*C*G*A*G*C*C*G*A*A*U*A*U*A* (SEQID NO:11) C*C, A*U*A*U*A*U*A*U*A*U*A*U*A*U*A*U*A*U* (SEQ ID NO:12) A*U,U*U*A*U*U*A*U*U*A*U*U*A*U*U*A*U*U*A* (SEQ ID NO:13) U*U,A*A*U*A*A*U*A*A*U*A*A*U*A*A*U*A*A*U* (SEQ ID NO:16) A*A,A*A*A*U*A*A*A*U*A*A*A*U*A*A*A*U*A*A* (SEQ ID NO:17) A*U,A*A*A*A*U*A*A*A*A*U*A*A*A*A*U*A*A*A* (SEQ ID NO:18) A*U,C*U*A*C*U*A*C*U*A*C*U*A*C*U*A*C*U*A* (SEQ ID NO:24) C*U, U*U*A*U*U*A*U,(SEQ ID NO:30) or U*A*U*A*U*A*U. (SEQ ID NO:33)


34. The ORN of claim 19, further comprising a nebulizer.
 35. The ORN ofclaim 19, further comprising an inhaler. 36-42. (canceled)
 43. A methodfor treating cancer comprising; administering to a subject in needthereof an ORN of claims 19 in an effective amount to treat the cancer.44. The method of claim 43, further comprising administering achemotherapeutic to the subject.
 45. The method of claim 43, furthercomprising administering radiation to the subject.
 46. A method fortreating asthma, comprising administering to a subject in need thereofan ORN of claim 19 in an effective amount to treat asthma.
 47. A methodfor treating allergy, comprising administering to a subject in needthereof an ORN of claim 19 in an effective amount to treat allergy. 48.The method of claim 47, wherein the subject has allergic rhinitis.
 49. Amethod for modulating an immune response in a subject, comprisingadministering to a subject in need thereof an ORN of claim 19 in aneffective amount to modulate an immune response.
 50. The method of claim49, wherein the ORN is delivered to the subject to treat autoimmunedisease in the subject.
 51. The method of claim 49, wherein the ORN isdelivered to the subject to treat airway remodeling in the subject. 52.The method of claim 49, wherein the ORN is administered without anantigen to the subject.
 53. The method of claim 49, wherein the ORN isdelivered by a route selected from the group consisting of oral, nasal,sublingual, intravenous, subcutaneous, mucosal, respiratory, directinjection, and dermally.
 54. The method of claim 49, wherein the ORN isdelivered to the subject in an effective amount to induce cytokineexpression.
 55. The method of claim 53, wherein the cytokine is selectedfrom the group consisting of TNFα, IL-10, IL-6, IFN-γ, MCP1, and IL-12.56. A method for treating asthma exacerbated by viral infection,comprising administering to a subject in need thereof an ORN of claim 19in an effective amount to treat the asthma exacerbated by viralinfection.
 57. A method for treating infectious disease, comprisingadministering to a subject in need thereof an ORN of claim 19 in aneffective amount to treat the infectious disease. 58-60. (canceled) 61.The method of claim 58, further comprising administering an anti-viralagent to the subject.
 62. The method of claim 61, wherein the anti-viralagent is linked to the ORN.
 63. (canceled)
 64. The ORN of claim 19,wherein the ORN motif is separated from a 5′ ribonucleotide by anon-nucleotide linker.
 65. The ORN of claim 19, wherein the ORN motif isseparated from a 3′ ribonucleotide by a non-nucleotide linker.
 66. TheORN of claim 19, wherein the ORN motif is separated from a 5′ and 3′ribonucleotide by a non-nucleotide linker.
 67. The ORN of claim 19,wherein the ORN is formulated in a polycationic carrier. 68-71.(canceled)
 72. A method for downregulating immunosuppressive CD4+regulatory (Treg) cells, the method comprising contacting a CD4+ Tregcell with a composition comprising an ORN of claim 19 in an effectiveamount to reduce inhibitory effect of the CD4+ Treg cell.
 73. The methodof claim 72, wherein the composition further includes animmunostimulatory CpG nucleic acid.
 74. The method of claim 73, whereinthe ORN and the immunostimulatory CpG nucleic acid are not linked. 75.The method of claim 73, wherein the ORN and the immunostimulatory CpGnucleic acid are present as a conjugate.